Chapter I Power on Fault

1、 Example of definition

The failure of the computer during the period from power on (or reset) to the completion of self inspection.

2、 Possible symptoms

1. The host cannot be powered on (for example, the power fan does not turn or stops after turning), sometimes cannot be powered on, the power is turned off, and the metal part of the chassis is charged;

2. No display when starting up, and alarm when starting up;

3. Self check error or crash, configuration displayed during self check is inconsistent with the actual, etc;

4. Repeated restart;

5. Unable to enter BIOS, crash or error after refreshing BIOS; CMOS power failure and inaccurate clock;

6. Other faults such as loud noise, automatic (timed) startup, power supply equipment problems, etc.

3、 Possible components

Electricity environment; Power supply, mainboard, CPU, memory, display card and other possible boards; BIOS settings (can be returned to factory status by discharging); Failure of switch and switch line, reset button and reset line.

4、 Key points/sequence of judgment

The following text description is a supplement and explanation to the maintenance judgment process, which should be read in combination with the flow chart. In addition, this chapter only analyzes power on faults. If other faults are involved in the judgment, the judgment process of corresponding faults can be transferred. The following categories are the same.

1. Preparation before maintenance

1) POST card;

2) Multimeter;

3) Test pencil;

4) CPU load.

2. Environmental inspection

1) Check computer equipment:

A. Whether there are deformation, discoloration, odor and other phenomena inside and outside the peripheral and computer equipment;

B. Environment temperature and humidity;

C. After power on, pay attention to whether the parts, components and other equipment are deformed, discolored, peculiar smell, abnormal temperature, etc.

2) Check the power supply:

A. Check whether the mains voltage is within the range of 220V ± 10% and whether it is stable (i.e. whether there is frequent power failure, instantaneous power failure, etc.);

B. Whether the connection definition of mains power is correct (that is, left zero and right fire, zero line is not allowed to be used as ground wire (the phenomenon is short circuit between zero and ground), and zero line should not be suspended or falsely connected);

C. Whether the power supply line is connected with a leakage protector (and must be grounded on the live wire), whether there is a ground wire, etc;

D. Whether one end of the host power cord is firmly and sadly inserted into the mains socket, and whether it should not be too loose or not inserted in place, and whether the other end can be sadly connected to the host power supply, and whether it should not be too loose or not inserted in place.

Chapter II Startup and Shutdown Faults

1、 Example of definition

Faults related to startup and shutdown process. Startup refers to the problem occurred in the process from the completion of self inspection to entering XX as the system application interface; System shutdown refers to all processes from clicking the shutdown button to disconnecting the power supply.

2、 Possible symptoms

1. Crash, error, black screen, repeated restart, etc. during startup;

2. A file error is reported during startup;

3. During startup, always perform some improper xx operations (such as always scanning disks, starting an abnormal application, etc.);

4. It can only be started in safe mode or command line mode;

5. Failure, error or crash during login;

6. When closing the xx operating system, it crashes or reports an error.

3、 Possible components

BIOS settings, startup files, device drivers, xx as system/application configuration files; Power supply, disk and disk drive, mainboard, signal cable, CPU, memory, and possibly other boards.

4、 Key points/sequence of judgment

　　 1. Preparation before maintenance

1) Disk data cable;

2) Multimeter;

3) Virus detection software.

2. Environmental inspection

1) Perimeter and appearance inspection of the machine:

A. Whether the mains connection is secure or not, and there should be no too loose or improper insertion;

B. Whether the indicator light of the host hard disk flashes correctly, and there should be no phenomenon that the indicator light is off or always on;

C. Observe whether the system has peculiar smell and whether the temperature of components is too high;

D. Observe whether the speed of CPU fan is insufficient, slow or unstable;

E. Listen to the driver for abnormal sound.

　 2) Drive connection check:

A. Check whether the power connection of the drive is correct. Whether the power connection socket on the driver has virtual connection;

B. Whether the jumper setting on the drive is consistent with the position where the drive is connected to the cable;

C. Whether the driver data cable is wrongly connected or missed, and whether the specification is consistent with the technical specification of the drive (for example, if the drive supports DMA66, 80 core data cable must be used);

D. Whether the driver data cable is faulty (such as exposed core wire, dead bend or hard mark, etc.) can be judged by observation, and can also be checked by replacing a data cable;

E. Whether the drive is connected to the system through other boards, or controlled through other boards (such as hard disk protection card, dual network isolation card, etc.).

　 3) Check the installation of other components:

A. Check whether the fault disappears by re plugging and unplugging components (including CPU and memory) (before re plugging and unplugging, dust removal and gold finger cleaning, including sockets, should be done first). If the problem is always solved by re plugging, check whether the components are too loose, whether the rear baffle size is not appropriate, and whether the socket is too tight to plug in place or be squeezed out during installation;

B. Check whether the CPU fan is in good contact with the CPU. It is better to reinstall it once.

4) Observation of displayed content: Pay attention to the contents of the screen error and the location of the crash to determine where the failure may occur.

　 3. Key points for fault judgment

1) Fully communicate with users, Understand the process that cannot be started and the user's xx actions;

　 2) BIOS setting check:

A. Whether the hardware of different models has just been replaced. If the BIOS on the motherboard supports the BOOTEasy function or the BIOS anti write switch is turned on, it is recommended to turn it off, and then turn it on after a complete start;

B. Whether new hardware has been added. At this time, the added hardware should be removed first to see whether the fault disappears. If so, check whether the added hardware has a fault or whether the settings in the system are correct (check by comparing the user manual of the new hardware);

C. Check the settings in BIOS, such as startup sequence, device parameters of startup disk, etc. It is recommended to restore by clearing CMOS;

D. Check whether the xx operating system cannot be started or shut down normally due to BIOS problems (including settings and functions). Try renaming BIOS.vxd (or VPBIOSD. vxd) in the Windows directory to BIOS.old, and then restart or shut down. If the fault disappears, fix it by modifying the BIOS device or updating the BIOS, otherwise it has nothing to do with BIOS. Note: After the test is completed, it must be changed back to its original name (Note: except for Windows 98, other xx operating systems do not have this file);

E. In some special cases, you should consider upgrading the BIOS to check. For example, if some applications or devices fail to work after the first boot, in addition to checking the device itself, you can consider updating the BIOS to solve the problem.

The following checks shall be carried out under the minimum software system.

3) Disk logic check:

A. According to the error prompt during startup, check whether the partition on the disk is correct, whether the partition is active, and whether it is formatted;

B. Directly check whether the hard disk is partitioned and formatted;

C. Add another drive (such as floppy disk drive or optical disk drive) without failure to check whether it can be started from another drive (if using floppy disk drive, it is better to use Seagate's detection floppy disk to start). If possible, check steps 3) and 4), otherwise check step 5); Next, whether the partition is activated and whether there are bad roads;

D. Whether the boot partition on the hard disk is activated, and whether there are boot files or commands used for boot;

E. Check whether the boot partition on the hard disk drive is accessible. If not, use the disk detection program of the corresponding manufacturer to check whether the hard disk is faulty. Replace the hard disk in case of failure; If there is no fault, it is detected by initializing the hard disk. If the fault still exists, replace the hard disk;

F. When other drives cannot be started, remove the hard disk drive first to see if it can be started. If it still cannot be started, check the components in the smallest system of software one by one, including the hard disk drive and the common components of disk transmission disk interface, power supply, memory, etc. If it can be started, it is better to initialize the hard disk once. If the fault does not disappear, replace the hard disk again;

G. If the hard disk needs to be initialized for xx operation, but the user has useful data, it is recommended that the user find a data repair company to solve the problem.

4) Xx checks the system configuration:

A. For the prompt of file error, the file should be repaired according to the corresponding software debugging method mentioned in Part I;

B. In case of failure to start, it is recommended to "select the last start" or use scanreg.exe to restore the registry to the previous backup registry to check whether the failure can be eliminated;

C. Check whether there are third-party programs running in the system, or improper settings or device drivers in the system cause abnormal startup. Pay special attention to the Autoexec.bat and Config.sys files here, and screen them to check whether the startup failure disappears;

D. Check whether the startup settings, keys in the startup group, key values in the registry, etc. have loaded unnecessary programs;

E. Check for viruses. It is required that only one anti-virus software can be installed in one system;

F. If necessary, check the startup failure by one click recovery, installation recovery and other methods;

G. When the display is abnormal during startup (such as black screen, blurred screen, etc.), it should be checked according to the judgment method of display fault, but first of all, pay attention to whether the driver of the display device is normal and whether the display settings are correct. It is better to change the display to the standard VGA mode for checking.

5) Hardware component inspection:

A. If the startup drive is connected through another control card, connect the drive directly to the default drive interface (on the motherboard);

B. When the system starts normally under the minimum software system, it should gradually return to the original configuration state to locate the components that cause the failure to start normally;

C. Pay attention to check the power supply capacity of the power supply, that is, whether the output voltage is within the allowable range, and whether the fluctuation range is beyond the allowable range (see the Maintenance Tool Manual);

D. Drive inspection can refer to the judgment method of disk fault;

E. In terms of hardware, we should start from memory: use the memory detection program to determine whether there is a failure in the memory part, install the memory from the first memory slot, and check whether the memory specifications of multiple installed memories are consistent and compatible. For memory specifications, please refer to the relevant parts of Appendix II.

6) The phenomena that cannot be shut down normally shall be checked from the following aspects:

A. View BOOTLOG at the command prompt TXT file (under the root directory). This file is the boot registration file. It records the failure of the system during operation. It saves a record of the system during normal operation. Compared with the record after the problem, it finds out the faulty driver in the WIN INI SYSTEM. Find the option corresponding to the driver in INI, or find the associated key value in the registry, change or upgrade the driver, which may solve the problem;

B. Upgrade the BIOS to the latest version, and pay attention to the CMOS settings (especially APM, USB, IRQ, etc.);

C. Check whether some system files are damaged or not installed (refer to Appendix II (III))

D. For problems caused by applications, close the applications in the startup group and check whether the sound program is damaged during shutdown;

E. Check whether a device, such as the network card and sound card, causes failure to shut down normally. You can check by updating the driver or changing the hardware;

F. Check the system by installing patches or upgrading xx;

G. For the shutdown problem of Windows 98SE system, please refer to Appendix II (III). One of them is also helpful for other Windows systems.

5、 Judgment process of this type of fault

6、 Case

Case 1:

Problem description: The client computer is installed with WIN 2000 PROFESSIONALxx as the system. The blue screen is displayed every time it is started, and MEMORY ERROR is reported.

Solution: Arrive at the customer, repeat the fault, and ask the customer about the situation. The customer said that a memory module was installed before the fault occurred, and then such a fault occurred. After power off, unplug the memory module and reboot. The screen is still blue, but MEMORY ERROR is no longer reported. Considering that WIN 2000 has high requirements for hardware and the fault occurs after the memory is installed, it can be concluded that the original hardware and software system of the machine are OK. Restart the computer again, press F8 when starting up, select "VGA mode", the computer can start normally this time, and the login is normal. After a normal login, restart to the standard mode, and the computer starts normally. So far, the fault is eliminated.

Case 2:

　 Problem description: A malicious program was run on the client machine, which caused a dialog box to appear after each startup, and the dialog box could not be closed, so it had to be forced to end. The client machine had important programs, and was unwilling to reinstall the xx operating system.

Solution: First, doubt whether it is a virus. Running common anti-virus software cannot check and kill it. Enter MSCONFIG in Start Run, but the program cannot be found in the Start group. Run "SCANREG" to restore the registry to the oldest version. Finally, you have to edit the registry manually, run "REGEDIT", and select "HKEY_LOCAL_MACHINESoftwareMicrosoftWindows

Under CurrentVersionRUN, find the corresponding program file name, delete the corresponding key value, restart, and troubleshoot. (Note: It is recommended to use the "Export" function of the registry editor to back up the registry before changing the registry.)

Chapter 3 Disk Faults

1、 Example of definition

The disk failures mentioned here represent two aspects: one is the failure caused by hard disk, optical disk drive, floppy disk drive and its media; The other is the failure caused by components (such as motherboard, memory, etc.) that affect the access to hard disk, optical drive, and floppy drive.

　 2、 Possible symptoms

1. Hard drive

1) The hard disk has abnormal sound and loud noise;

2) The BIOS cannot correctly identify the hard disk, the hard disk indicator is always on or off, and the hard disk interferes with the work of other drives;

3) Cannot partition or format, incorrect hard disk capacity, bad hard disk, data loss, etc;

4) The drive letter of the logical drive is lost or changed, and an error is reported when accessing the hard disk;

5) Hard disk data protection failure;

6) Hard disk failure caused by third-party software;

7) Failure caused by hard disk protection card.

2. Floppy disk drive

1) The floppy drive indicator is not on or always on, and the floppy drive makes a loud disk reading sound;

2) The floppy disk is scratched, and cannot be ejected or inserted;

3) The floppy disk cannot be formatted, the floppy disk drive does not read the disk, or the floppy disk drive interferes with the normal operation of other drives or devices or applications;

4) Files written in one floppy drive cannot be read in another floppy drive;

5) The floppy drive letter is lost or changed, or an error occurs when accessing the floppy drive;

6) The floppy drive is not properly installed.

3. Optical drive

1) The optical drive is noisy, the optical drive is scratched, the optical drive tray cannot be ejected or closed, and the optical drive reading ability is poor;

2) The optical drive letter is lost or changed, and the system cannot detect the optical drive;

3) Crash or error when accessing the optical drive;

4) The optical disk drive does not work properly due to the optical disk media.

3、 Possible components

Hard disk, optical disk drive, floppy disk drive and their settings, disk interface, power supply and signal cable on the motherboard.

4、 Key points/sequence of judgment

1. Preparation before maintenance

1) Disk data cable;

2) Corresponding disk detection software;

3) Virus detection software, etc.

2. Hard drive

1) Environmental inspection

A. Check the hard disk connection:

a) Whether the ID jumper on the hard disk is correct, and it should match the position on the connecting cable;

b) Whether the data cable connected to the hard disk is connected incorrectly or reversely;

c) Check whether the hard disk connection cable is damaged or hard creased. It can be checked by changing the connecting line;

d) Whether the connection cable type of the hard disk is consistent with the technical specifications of the hard disk;

e) Whether the hard disk power supply has been correctly connected, and there should be no loose or improper insertion.

B. Hard disk appearance inspection:

a) Whether the components on the hard disk circuit board are deformed, discolored, broken or defective;

b) Whether the pin of the hard disk power socket has faulty soldering or desoldering;

c) After power on, whether the indicator light is off or always on during hard disk self inspection; Whether the indicator light flashes normally during operation;

d) After power on, listen to whether the operation sound of the hard disk drive is normal without abnormal sound and excessive noise.

C. Check the power supply of the hard disk:

a) Whether the power supply voltage is within the allowable range, and whether the fluctuation range is within the allowable range, etc.

2) Key points for fault judgment

A. It is recommended to check under the minimum software system and judge whether the fault phenomenon disappears. This eliminates the impact of other drives or components on hard disk access.

B. Parameter and setting check:

a) Whether the hard disk can be correctly identified by the system, and whether the identified hard disk parameters are correct; Whether the transfer mode of IDE channel is set correctly in BIOS (preferably "Automatic");

b) Whether the displayed hard disk capacity is consistent with the actual, and whether the formatted capacity is consistent with the actual (note that the nominal capacity is generally marked in 1000 units, while the BIOS and formatted capacity are displayed in 1024 units, and there is a gap of 3%~5% between the two. In addition, the formatted capacity is generally smaller than the capacity displayed in BIOS). The capacity of the hard disk should be much smaller than the actual capacity according to the functions provided by the system (such as one button recovery). Please refer to the relevant instructions in the user manual for the reduced value;

c) Check whether the technical specifications of the current motherboard support the technical specifications of the hard disk used, such as: support for hard disks larger than 8GB, support for high transmission rate, etc;

C. Check the logical structure of the hard disk: refer to the relevant parts in the key points for judging startup failures.

a) Check whether the partition on the disk is normal, whether the partition is activated, formatted, and whether the system file exists or is complete;

b) For the hard disk that cannot be partitioned and formatted as xx, the hard disk should be replaced without virus. If the replacement is still invalid, check whether the hardware components under the minimum system of software are faulty;

c) Repair or initialize xx operation when necessary, or completely reinstall xx operation system;

D. Check the system environment and settings: refer to the relevant parts in the key points of starting fault judgment.

a) Check whether there are viruses in the system, especially boot viruses (such as KV3000/K command or MEM.EXE command);

b) Carefully check whether there is a third-party disk management software running in the xx operating system; Whether the IDE channel is properly set in the device manager;

c) Whether the improper service is enabled. It should be noted here that the ATA driver may be abnormal in some applications. It is recommended to uninstall it and check whether the abnormal phenomenon disappears;

E. Hard disk performance check:

a) After power on, if the hard disk sounds abnormal, does not work at all or does not work normally, check whether the power supply is faulty, whether the data cable is faulty, whether the BIOS setting is correct, etc., and then consider whether the hard disk itself is faulty;

b) The hard disk detection program provided by the corresponding hard disk manufacturer shall be used to check whether the hard disk has bad tracks or other possible faults;

F. For the problems caused by the hard disk protection card, the following aspects should be considered:

a) When installing the hard disk protection card, you should turn off the virus warning in CMOS, set the mapping address in CMOS to disable, and set the first boot device in CMOS to LAN; The optical drive and hard disk should be connected to different IDE data lines.

b) If you forget the administrator password of the hard disk protection card, for version 1.0 ALT+133, ALT+144, ALT+155, 10 groups will pop up (you must use the keypad). For version 3.0, enter ENPQ at the administrator password, get a group of data, and then dial 800 to get the password;

c) If the machine with the hard disk protection card has a red screen when it is turned on, it should use a special tool program to solve the problem. For the method, please refer to the relevant Technical Engineering Information Bulletin;

d) If some data disks cannot be seen under a boot disk, check whether these data disks are exclusive to the boot disk; Whether the partition type is recognized by xx of the boot disk; Whether a FAT16 partition belonging to the boot disk has been established after 8GB on a hard disk larger than 8GB (of course, the boot disk supports the FAT16 file system); Whether the boot disk has more than 3 exclusive partitions;

e) The hard disk protection card does not have the protection function. To check whether the user has turned off the hard disk protection function, press F4 to enable the hard disk protection function before entering the system (it should have been installed in advance). If not, you can reinsert the hard disk protection card. Under Windows, check whether the driver software has been installed;

f) When the hard disk protection function is enabled, the original system on the hard disk will not be retained. You should ask the user whether the original system is partitioned by third-party software. At present, the hard disk protection card can only protect the system partitioned by using xx as the FDISK of the system itself;

g) In the hard disk protection mode, it is restored every time. If there are multiple prompts for disk scanning due to the failure to shut down normally, you should add an autoscan=0 item in the Msdos.sys file in the administrator mode;

h) For garbled code in user mode, run SETUP in the upgrade disk in administrator mode EXE;

　 3. Floppy disk drive

1) Environmental inspection

A. Under certain circumstances, floppy disk drive is similar to the check method of hard disk drive.

B. Check the floppy drive connection:

a) Whether the connecting cable is correctly installed, and there should be no wrong or wrong insertion;

b) The location of the floppy drive connection should be consistent with the value set in the BIOS;

c) Whether the power connection of the floppy drive is correct.

C. Floppy drive appearance inspection

a) Whether there is foreign matter in the floppy drive;

b) Whether there are deformation, discoloration, odor and other phenomena on the circuit board and its components.

D. Whether the quality of the floppy disk media used is too poor;

2) Key points for fault judgment

A. To check the floppy drive, add the floppy drive to the minimum software system, or check and judge after removing the hard disk. If necessary, remove it from the chassis for inspection;

B. Similar to the check of hard disk drive. However, it should be noted that whether the setting of whether the floppy drive is readable or writeable in the BIOS is allowed or disabled;

C. Check the read and write ability of the floppy disk drive. On the one hand, check its own read and write ability. On the other hand, check the interchangeable read and write ability of the floppy disk, that is, whether the floppy disk written in the possibly faulty floppy disk drive can be read in another normal floppy disk drive. If not, replace the floppy drive;

D. Floppy disks are the media most susceptible to viruses, so we must pay attention to virus detection during the inspection.

4. Optical drive

1) Environmental inspection

A. Check the optical drive connection:

a) Whether the ID jumper on the optical drive is correct, and it should match the position on the connecting cable;

b) Whether the data cable connected to the optical drive is connected incorrectly or reversely;

c) Whether the optical drive cable is damaged or hard folded. It can be checked by changing the connecting line;

d) Whether the type of optical drive cable is consistent with the technical specifications of the optical drive;

e) Whether the optical drive power supply has been correctly connected, and there should be no loose or improper insertion.

B. Optical drive appearance inspection:

b) Whether the components on the optical drive circuit board are deformed, discolored, broken or defective;

c) Whether the contact pin of the optical drive power socket has faulty soldering or desoldering;

d) After power on, whether the LED is off or always on during the self check of the optical drive; Whether the indicator light flashes normally during operation;

e) After power on, listen to whether the operation sound of the optical drive drive is normal without abnormal sound and excessive noise.

　 2) Key points for fault judgment

A. The optical drive shall be checked and judged by the hard disk in the smallest system of the optical drive replacement software. If necessary, remove it from the chassis for inspection. When checking, use a bootable disc to start, so as to preliminarily check the failure of the optical drive. If it cannot be read normally, check it in the software minimum system. The optical drive was first investigated;

B. Inspection methods similar to hard disk drives;

C. Optical drive performance check:

a) For the fault with poor disk reading ability, first consider the impact of anti-virus software, and then use the random CD for detection, such as fault recurrence, replacement and maintenance, otherwise, according to the user's needs and the fault seen, the corresponding treatment will be carried out;

b) If necessary, refresh the formware of the optical drive to check whether the failure of the non drive disappears (if a CD is placed in the optical drive, which causes the optical drive to work abnormally when the system starts for the first time, try this method);

D. Xx performs configuration check in the system:

a) Whether the application software under the xx operating system can support the technical specifications of the optical drive currently used;

b) Whether the settings in the device manager are correct, and whether the IDE channel settings are correct. If necessary, uninstall the optical drive and restart it, so that xx can re recognize the system.

5、 Judgment process of this type of fault

6、 Case

Case 1:

Problem description: Xiao Wang is a computer maintenance personnel in a company. His office computer is Lenovo's Benyue 2000 model with 13G hard disk. Since the system and data in the computer have not been maintained for a long time, the system starts and runs slowly. He copies the important data on disk C to disk D, and then runs Lenovo's system recovery software, Copy the Windows98SE system in the hidden partition to disk C. After less than 10 minutes, restart again and enter the Windows 98 system normally. But after entering the system, it is found that the original extended partition divided by PM is missing. A large amount of data is in the extended partition. What should I do? Xiao Wang is in an awkward situation

Solution: First, check the random data of Lenovo machine. The manual says, "Maybe the partition format of PM, etc. is not supported. Please use Fdisk when partitioning..." It may be that the original hard disk partition table was damaged during system recovery. Is there any solution? I can enter MSDos or PM for the machine, When a primary partition and an extended partition have no other partition information, the software Diskman comes to mind, enters MSDos, runs Diskman, and first warns that the partition table is wrong. Although Diskman still recognizes the hard disk as two partitions, it still has the function of re detecting the partition table. There are two ways to re detect the partition table: fully automatic and interactive. When the latter is selected, Diskman starts to detect the existing partition table on the hard disk cylinder by cylinder. After a long time, the original three partitions, including the backup partition hidden by Lenovo's system recovery software, were detected. The partition format was maintained and everything was normal.

Comment: Power failure in the user's application or when the user partitions the hard disk will lead to errors in the hard disk partition table. Don't worry when encountering such problems. Analyze the cause of the problem, check relevant information, such as relevant software and information attached to the computer, and solve the problem with relevant software or tools The application of relevant software or tools is not well understood, so you must look up relevant information or ask people.

Note: Diskman hard disk partition table maintenance software, running in MSDOS environment, adopts full Chinese graphical interface, without any Chinese character system support. The detailed structure of the partition table is revealed in the form of a chart, which supports xx mouse operations, large hard disks of more than 8G, UNIX, NTFS and other partition formats.

Case 2:

Problem description: One user, Tianxi II 5311, reported that when formatting a rewritable disc (BenQ CD-RW) with the FileCD tool in the random software NTI CD Maker Plus, the progress quickly reached 100%, but without a prompt to complete the formatting, the dialog box could not be closed by force. Finally, I had to finish the task. Burn the hard disk with NTI CD Maker Plus, and the recording progress will be displayed during the recording process. After the recording is completed, put the recorded disc into the disc drive, and the disc cannot be recognized.

Solution: First, consider the software problem of the plug-in FileCD in the NTI CD Maker. Upgrading the NTI CD Maker software to V5.08 and V5.13 did not solve the problem. Upgrading to V5.15 is still the same. Then, see that the version of the FileCD is the same as the version of the user's original FileCD. The function of rewriting the CD has not been improved in subsequent versions of 2.0.10. Consider selecting another recording software, use NERO to test (version V5.5.9.0), use this software to perform fast rewriting, and then burn the disc. The above phenomenon still occurs. However, using SONY CD-RW discs does not cause this problem.

Comment: When erasing a disc, it has a lot to do with the recording software and recorder. The engineer can consider the problem from multiple perspectives when solving the problem.

Case 3:

Problem description: A user bought an optical drive after its warranty. According to the user's report, the optical drive was tested when he bought an optical drive in the market, and there was no problem. The tested data disk and VCD and other optical disks could be read normally. But after he returned home and installed an optical drive, he turned on the computer to enter the system, and all the discs placed in the optical drive only displayed CD like marks on the drive letter. The user returns to the place of purchase to install the optical drive on the test machine, and the problem reappears.

Solution: After inspection, it is found that a data cable on the data interface of the optical drive is bent, which causes the data in the drive to be unrecognizable.

Chapter IV Display Fault

1、 Example of definition

Such failures not only include failures caused by display equipment or components, but also include abnormal phenomena in display caused by poor other components. In other words, the display failure is not necessarily caused by the display equipment, and it should be comprehensively observed and judged.

2、 Possible symptoms

1. There is no display when starting up, and the display sometimes or often cannot be powered on;

2. Display color deviation, dithering or scrolling, false display, blurred screen, etc;

3. In some application or configuration, the screen is blurred, darkened (or even black), ghosted, or crashed;

4. Screen parameters cannot be set or modified;

5. The brightness or contrast is not adjustable or the adjustable range is small, and the screen size or position cannot be adjusted or the range is small;

6. Abnormal display after sleep wake-up;

7. The display smells or sounds.

3、 Possible components

Display, display card and their settings; Mainboard, memory, power supply, and other related parts. Pay special attention to the interference of other equipment around the computer and geomagnetism to the computer.

4、 Key points/sequence of judgment

1. Preparation before maintenance

The latest driver for the corresponding display card

　 2. Environmental inspection

1) Mains power inspection:

A. Whether the mains voltage is 220V ± 10%, 50Hz or 60Hz; Whether the mains power is stable;

B. For the rest, refer to the relevant mains power inspection part in the power on fault.

2) Connection check:

A. The connection between the monitor and the host is firm and correct (pay special attention to whether two display ports are connected to the correct display port when there are two display ports); Check whether the pin of the cable connector is deformed or broken, and check whether the quality of the displayed cable is intact;

B. Whether the display is correctly connected to the market power, and whether its power indication is correct (whether it is bright and color);

C. Displays whether the abnormality of the equipment is related to the ungrounded wire. Special attention: the computer maintenance engineer is not allowed to install the ground wire for the user, and the user should be asked to install it through a formal electrician;

3) Inspection of surrounding and host environment:

A. Check whether the ambient temperature and humidity are consistent with the manual (for example, the required operating temperature of diamond tube is 18~40C);

B. Whether there is odor, smoke or abnormal sound (such as popping sound) after the display is powered on;

C. Whether the components on the display card are deformed, discolored, or the temperature rises too fast;

D. Whether the display card is properly inserted can be checked by reinserting, wiping the golden finger part of the display card (including other boards) with rubber or alcohol; If there is much dust in the host, remove it;

E. Whether there are interferences in the surrounding environment (these interferences include fluorescent lamps, UPS, speakers, hair dryers, other displays that are too close to each other (within 50 cm), and other high-power electromagnetic equipment, cables, etc.). Note that the display direction may also interfere with the display equipment due to the influence of geomagnetism;

F. For color deviation, jitter and other failures, check whether the failure disappears by changing the direction and position of the display.

4) Other inspection and precautions:

A. After the host is powered on, whether there are normal self-test and operation actions (if there is a beep after self-test, the hard disk indicator light keeps flashing, etc.). If there is, focus on the display or display card;

B. It is forbidden to move the display and its direction with power on. It is better not to move the display for a period of time (2-3 minutes) after power off.

　 3. Key points for fault judgment

1) Adjust the monitor and display card:

A. By adjusting the OSD option of the display, it is better to return to the RECALL (factory state) state to check whether the fault disappears. For the LCD, press the auto config button;

B. Whether the parameters of the display are set too high or too low (such as H/V-MOIRE, which cannot be recovered through RECALL);

C. Whether the buttons on the display can be adjusted, and whether the adjustment range deviates from the specifications of the display;

D. Whether the abnormal sound or smell of the display exceeds the requirements of the technical specifications of the display (for example, when a new display is just used, there will be abnormal smell; when it is just powered on, there will be sound and screen shake caused by demagnetization, but these are normal phenomena). See Appendix II (II) for the specifications of the display;

E. Displays whether the card's technical specifications can be used in the host (such as whether the AGP 2.0 card can be used in the AGP slot of the host).

2) BIOS configuration adjustment:

A. Whether the settings in the BIOS match the type of display card currently used or the location where the display is connected (that is, whether to use an on-board display card or an external display card; whether to use an AGP display card or a PCI display card);

B. For on-board display cards that do not support automatic allocation of display memory, check whether the size of the display memory in the BIOS meets the needs of the application;

The following checks shall be carried out under the minimum software system.

3) Check the drive of the display/card:

A. Whether the driver of the display/card matches the display device and the version is appropriate;

B. Whether the display driver is correct. If there is a driver provided by the manufacturer, it is better to use the manufacturer's driver;

C. Whether the appropriate Direct X driver (including mainboard driver) is loaded;

D. If the Direct X driver is installed in the system, you can use the Dxdiag.exe command provided by it to check whether the system is faulty. This program can also be used to check the sound card equipment.

4) Check the display properties and resources:

A. Check whether there are resource conflicts between other devices and the display card in the device manager. If there are, remove these conflicting devices first;

B. Whether the display properties are properly set (such as incorrect monitor type, refresh rate, resolution and color depth, which may cause ghosting, blurring, blurred screen, jitter, or even black screen);

5) Xx conducts system configuration and application inspection:

A. Whether the settings in some configuration files (such as System.ini file) in the system are appropriate;

B. Whether the technical specifications of the display card or the functions of the display driver support the needs of the application;

C. Whether there are other software and hardware conflicts.

6) Hardware check:

A. When the display adjustment is normal, add other parts one by one to check what causes the abnormal display;

B. Check whether there is a matching problem between display cards or monitors of different models;

C. Check whether the display is abnormal due to hardware failure by replacing the corresponding hardware (the recommended replacement sequence is: display card, memory, motherboard).

5、 Judgment process of this type of fault

See Appendix I (IV).

6、 Case

Case 1:

Problem description: I have encountered such a machine, and the phenomenon is quite strange. The model is the Pentium 2000 PIII/800. The fault is that there is no display after frequent startup. Sometimes the display can enter the system, but after 1-2 hours of use, there will be a crash, restart and no display. Only after a long time of restart, the display can be displayed.

Solution: When encountering this problem, first determine that it should be a hardware problem, open the chassis, check that each board card is not loose (note: the Lenovo sticker on the graphics card and the motherboard socket is very tight), replace the parts and try it. The memory, CPU, and power supply have been replaced successively, but none of them can solve the problem. Then replace the motherboard. When removing the Lenovo sticker on the graphics card and the motherboard socket, I feel that the graphics card is not inserted in place, Press it down, and it can go in a little more, so I doubt whether it is caused by poor contact between the graphics card and the motherboard, so I restored all the original parts of the machine, and tested the machine, and everything was normal.

Postscript: This case is a strange fault caused by the poor contact of the video card. The maintenance process is complicated due to the omission during the inspection (only to check whether the video card is firmly inserted, but not actually check it).

Case 2:

Problem description: A moon running machine, the user said that every time he started it, he could not enter WIN98, and the cursor stayed at the top left corner of the screen, flashing, and the machine crashed; However, safe mode can be accessed.

Solution: It is suspected that it is caused by improper settings of the graphics card or monitor. Enter the security mode, set the display resolution to 640 * 480, and set the color to 16 colors. Restart, and you can enter in the normal mode. However, as long as you change the resolution or color, the machine cannot start normally; Look inside the machine. There is no other configuration except for the user adding a network card. Is there a conflict between the network card and the video card? Unplug the network card, and you can start WIN98 normally. Change a slot for the network card. When you start up, new hardware is detected. After loading the driver, you can start up. Everything is normal.

Postscript: In case of a crash caused by incompatibility or conflict between the graphics card and other components, the minimum systematization method can be used to test first (the minimum systematization method means that only the main components such as the motherboard, CPU, graphics card and power supply are retained). The main components should be excluded first, and then other expansion cards should be tested one by one.

Case 3:

Problem description: The Delta Force, the Land Warrior, runs on the 810 (e) series motherboard (Jubilee and Daily series). If you install the video card driver with a random disk (and it is our usual style to install the driver with a random disk), when you enter the game screen, it will inevitably lead to a crash.

Solution: The solution is to download a new version of the driver from the Internet and upgrade it.

Postscript: If you encounter a crash while playing 3D games during actual maintenance, it is estimated that it may be a graphics card failure without replacement of spare parts (which is often encountered during our on-site maintenance), you can download a Direct control software from the Internet to block AGP support. Play 3D games again. If there is no crash, it means that the problem is probably somewhere else (such as the motherboard and memory). If the computer crashes, it means that the video card is faulty to a large extent.

Case 4:

Fault description: Kaitian 2200 P4/1.7G (QDI P7LI-AL motherboard), when running Huaguang Chaoen group software (with an ISA encryption card), if it is magnified, the left boundary cannot be displayed.

Solution: When the user buys a new machine, the agent has a problem installing the Super En software for the user. A new machine was replaced, but the fault was still the same. The agent judged that the Huaguang ISA card was incompatible with this model, and asked the maintenance station to solve it. The fault reappears at the user's location, and the display is normal when a PCI graphics card is inserted. It is estimated that the fault is not a machine fault. In the system properties - performance - graph, turn down the hardware acceleration by two spaces to solve the problem.

　 Chapter V Installation Faults

1、 Example of definition

This kind of failure is mainly reflected in the failure of installing xx as the system or application software.

2、 Possible symptoms

1. When installing the xx operating system, the system crashes or reports an error during file copying; System crash or error report during system configuration;

2. Error, restart, crash, etc. (including replication and configuration process) when installing application software;

3. After the hardware equipment is installed, the system is abnormal (such as black screen, non startup, etc.);

4. The application software cannot be installed or uninstalled after uninstallation.

3、 Possible components

Disk drive, motherboard, CPU, memory, and other possible components and software.

4、 Key points/sequence of judgment

1. Preparation before maintenance

1) Pay attention to carrying the disk data cable;

2) The latest version of the appropriate device driver.

2. Environmental inspection

1) Software installation

A. Check the connection and appearance of hardware devices:

a) Check whether other equipment connected to the host works normally;

b) Whether the connecting line between the equipment is wrongly connected or missed. Check whether the connecting pins of the plug and seat are deformed, missing or short circuited;

c) Carefully check the error message and determine the position that may cause the fault;

d) Observe whether the system has peculiar smell and the temperature of components;

e) Whether the speed of CPU fan is too slow or unstable;

f) Whether there is abnormal sound when the driver is working.

B. Other inspection:

a) Carefully compare the software manual and confirm that the software and hardware configuration of the machine meet the requirements of the manual;

b) Carefully observe whether the installation medium is intact.

2) Equipment installation

A. Check the connection and appearance of the equipment:

a) Whether the equipment and components to be installed are correctly connected, whether the connecting cable is intact, and whether the contact pin is missing, broken, or short circuited;

b) Whether the manufacturing process of the equipment and components to be installed is good;

c) Other similar software installation.

B. Driver Media Check: Whether the driver media used to install the device is intact.

3. Key points for fault judgment

1) Xx for system installation:

A. Check the settings in CMOS:

a) If necessary, please restore to the factory settings first;

b) Turn off the BootEasy function, the anti-virus function, and the BIOS anti write switch;

c) Pay special attention to hard disk parameters, CPU temperature, etc. Observe whether the information displayed during self inspection is consistent with the actual hardware configuration.

B. Check installation media and target media:

a) Check whether there is virus;

b) Check whether the partition table is correct and whether the partition is activated. Use the Fdisk/mbr command to ensure that the master boot record is correct (note that after using this command, if the machine cannot be started, it can prove that there is a virus or error in the original system. The hard disk should be initialized xx);

c) Check whether there is a third-party memory resident program in the system.

It is recommended to check the following procedures under the minimum system of software (note: under the minimum system, other drivers related to installation need to be added).

　C. Inspection during installation:

a) If a file error such as CAB is reported when copying a file, you can try to copy the original file to another media (such as a hard disk) before installing it. If it passes normally, there is a problem with the original installation media. You can check whether the media and the corresponding drive are faulty; If it still cannot be copied, check the corresponding disk drive, data cable, memory and other parts;

b) If the above problem occurs due to overwrite installation, it is recommended that if the failure cannot be eliminated after replacing the installation media, the hard disk should be initialized for xx operation first, and then reinstalled (when initializing xx operation, it is better to clean the hard disk partition completely). If it still cannot be solved, consider the hardware again;

c) During installation, error prompt, blue screen or crash occurs when detecting hardware. First, restart several times (it should be shutdown and restart) to see whether it can pass; The other is to check whether it can pass under the minimum software system. If it fails, check the memory, disk, CPU (including fan), power supply and other components in the smallest system of software in turn; If it can be installed normally, it is the fault or configuration problem of components other than the minimum system of software. This can be determined by gradually adding those components after installation and judging whether there is fault or improper configuration;

D. Hardware and other problems to be noted:

a) If the system is restarted or powered down during installation, it is required to test under the minimum software system. If the fault disappears, after the system is installed, connect the equipment other than the smallest system of software one by one, check which component is responsible for the fault, and use the replacement method to solve it; If the fault cannot disappear, check the power supply, motherboard, memory, and even disk drive in the smallest system of software;

b) When installing a UNIX xx operating system on an IDE device, or when installing multiple xx operating systems, pay attention to: first, the 8.4GB limit (the beginning of UNIX must be within 8.4GB) - this requirement is not applicable to SCSI devices; The other is the installation sequence and cooperation relationship between multi xx operating systems;

E. Pay attention to the following points when installing LEOS:

a) Ensure that the motherboard BIOS supports LEOS. It is recommended to refresh the BIOS that supports LEOS after replacing the motherboard for the user;

b) If you replace the hard disk for the user, you should also pay attention to whether the spare hard disk correctly supports DMA66. Otherwise, there will be problems when installing LEOS;

c) It is better to install LEOS on a new non partitioned hard disk. The specific sequence can be referred to the following scheme: new hard disk ->install LEOS ->partition (Fdisk) ->install xx as the system (Windows XP) ->create one click recovery. If the original hard disk has partitions, you can use the Clear.com program to clear them before installing LEOS.

2) Application software installation:

A. Precautions for checking the installation of application software:

a) For installation problems of application software, refer to the above xx for system installation inspection methods;

b) Before installation, it is required to back up the registry before installation;

B. Conflict check between software and hardware:

a) Two software problem isolation methods can be used. First, in the system with the smallest software, close the running application, and then install the required application software; The other is to close the running application directly under the original system, and then install the required application software. The method to close existing applications is: use msconfig to disable the programs called at startup in the startup group, autoexec.bat, config.sys, win.ini, and system.ini;

b) Use the task manager to check whether there are abnormal processes in the system and kill them;

c) For the situation that basically meets the requirements of the software technical manual but cannot be installed, see whether it can be solved through setting adjustment. If it cannot be solved, it will be regarded as incompatible;

d) Use other machines (preferably with different configurations) to check whether there are compatibility problems in software and hardware;

e) Check whether the software has been installed in the system. If it has been installed, uninstall it before installing it. If it cannot be uninstalled normally, you can uninstall it manually or by restoring the registry (for Windows XP, you can use the system restore function to uninstall);

f) If necessary, you can consult relevant information on the network, and then contact the software manufacturer to see if there are other precautions.

C. Hardware check:

If the above steps do not work, consider the hardware problem, and check the optical drive, installation media, hard disk cable and other accessories.

3) Hardware device installation:

A. Conflict check:

a) Whether the installed equipment and components are identified in the self inspection process before system startup, or can be identified by xx as the system (except for non plug and play identification). If it cannot be identified, check the BIOS settings and the device itself, including jumpers and corresponding slots or ports;

b) Check whether the newly installed equipment conflicts with the equipment in the original system; Check whether the fault is eliminated by changing the installation sequence of the drive, removing the corresponding parts or equipment in the original system, and replacing the slots. If it cannot be eliminated, it is incompatible;

c) Whether the added equipment matches the technical specifications or physical specifications of the existing system;

d) Check whether some settings in the current system (mainly the settings in the. ini file) do not match the installed components or device drivers;

B. Driver check: whether the installed device driver is the appropriate version (that is, not necessarily the latest);

C. Hardware check:

a) Whether the installed components or equipment are faulty;

b) Check whether the components in the original system are defective (such as damaged slots, insufficient power supply, etc.).

5、 Judgment process of this type of fault

See Appendix I (V).

6、 Case

Case 1:

Problem description: When the user reported to repair the Tianxi 6620 machine, during the installation of 98, he was prompted that there were three minutes left. Hwinfo reports an error and cannot be installed normally.

Solution: After the engineer came to the house, after testing, there was really a problem that the user responded to. Then try to copy the installation file to the hard disk for installation and replace it with another installation disk. The failure remains. Then check the BIOS and find that the system date is 2075. After the date is changed back, the fault is eliminated. Although the problem is small, the impact is big. Here, I would like to remind everyone to be careful and not ignore every detail.

Case 2:

Problem description: 2000 machines every day suddenly crashed and could not be started. The system could be reinstalled successfully, but there were many question marks in the device management, such as the print port and COM port, which were not driven.

Solution: Reinstall the system in the station, and the drive motherboard cannot solve the problem. It seems that only the host can be replaced. Open the chassis and find there is a lot of dust. Take out the motherboard and clean it. With the heart of trying, reinstall everything.

Case 3:

Problem description: A user of the Benyue 4000 machine/PIII 1G, who was a unit technician, said that the machine could not be reinstalled. Every time the machine was reinstalled, it would crash, and he asked for on-site maintenance.

Solution: When I arrived at the user, I found that there was no response when I reinstalled the detection hardware. When I opened the machine for inspection, I found that the CPU fan was not Lenovo. The customer said that this was just taken from the market, new, no problem. It is useless to replace the hard disk and memory in turn. After the user agrees to take them back to the toaster in the station and replace the motherboard and CPU, it still does not work. After repeated retries, it is found that each time the dead time is getting shorter and shorter. It is suspected that there is a problem with the CPU fan. The problem was solved by replacing the fan on another Lenovo machine. The cause of the fault is that the customer's CPU fan speed is not enough, which causes a high temperature crash.

Chapter VI Operation and Application Faults

1、 Example of definition

This kind of fault mainly refers to the application and system faults that occur after startup and before shutdown.

2、 Possible symptoms

1. Unable to wake up normally after sleeping;

2. Blue screen, crash, illegal operation and other failures occur during system operation;

3. The system runs slowly;

4. Running an application program results in hardware function failure;

5. The game cannot run normally;

6. The application is not working properly.

3、 Possible components

Mainboard, CPU, memory, power supply, disk, keyboard, plug-in board, etc

4、 Key points/sequence of judgment

1. Preparation before maintenance

1) Clean and usable hard disk;

2) Anti-virus software;

3) New drivers and several versions of BIOS as far as possible;

4) Data cable connected to the disk.

2. Environmental inspection

1) Mains power and connection inspection:

A. Check whether the mains power is normal and whether the connection is sad; Whether there is grounding;

B. Whether the connecting line between the equipment is wrongly connected or missed.

2) Perimeter and appearance inspection:

A. Check whether other peripherals connected to the host work normally;

B. Whether there is abnormal noise when the driver is working, and whether the speed of the CPU fan is too slow or unstable;

C. Observe whether there is too much dust in the chassis, resulting in poor contact between the connectors. After dust removal, wipe the gold finger with rubber to remove the oxide layer or dust. Then plug it in again;

D. Observe whether the system has peculiar smell and whether the temperature rise of components is too high or too fast.

3) Display and setting check:

A. Record the error information in detail and judge the position that may cause the fault;

B. Pay attention to the settings of hard disk, system time and CPU temperature in CMOS, and check whether the hardware information displayed during self inspection is consistent with the machine configuration;

C. Read the guide carefully and pay attention to the environment requirements for software operation.

4) Fully communicate with users:

A. Understand the usage of users;

B. Phenomenon before failure;

C. What operation has been done before the current fault occurs.

According to the above information, the possible fault causes can be preliminarily judged.

3. Key points for fault judgment

1) Check whether it is caused by user's misoperation

A. In case of machine crash, blue screen or restart without reason, first consider whether the user's operation conforms to the operation specifications and requirements, carefully inquire and observe whether the user's operation method conforms to the common sense, and the engineer shall operate and apply the user's machine with the correct method to check whether there is any fault reported by the user. If it does not appear, it can be considered that it is caused by the user's improper operation, and the engineer will explain and demonstrate the correct operation method to the user.

B. If the failure still exists after the above operations, you can use the System File Checker to check whether the user's machine system has a missing DLL file and try to recover it.

C. Pay attention to observe whether the user's machine is regular when it crashes, blue screen or restarts for no reason, and find out the reasons that may cause the machine failure (such as when the machine is running a program or when the machine is turned on for a certain period of time).

D. By comparing with another machine with the same software and hardware and no fault, check whether the file size of the fault machine is the same or not different, and whether the version of the main program is the same.

2) Check whether the failure is caused by a virus or antivirus program

A. Check whether the user's machine is infected by virus, and use anti-virus software to kill virus;

B. Check whether the user has installed two or more anti-virus software. It is recommended that the user use one of them and uninstall other anti-virus software;

C. Check whether there is a trojan program. Use the latest anti-virus program to find out the trojan program. You can install patches to remedy security vulnerabilities in the program, or install firewalls.

3) Check whether the failure is caused by operating system problems

A. Check whether the hard disk has enough free space, and check whether there are too many temporary files. Organize hard disk space and delete unnecessary files;

B. If the system file is damaged or lost, you can use the System File Checker to check and repair it;

C. Check whether the operating system has installed appropriate system patches (SP6 is recommended for Winnt to observe the service pack version at startup; SP3 is recommended for Win2k and Winxp, and SP1 is recommended for Winxp);

D. Check whether the DirectX driver is normal, and upgrade the version of DirectX;

E. Check whether the device driver is correctly installed and whether the driver version is appropriate. Check whether the driver installation sequence is correct (for example, install the mainboard driver first).

4) Check whether the failure is caused by software conflict and compatibility

A. Check whether the operating environment of the user's application software is compatible with the existing operating system (NT/98/2K/XP). You can check the software manual or the application software website for relevant information, and check whether there is an upgrade program or patch for this software available on the website.

B. You can use the task manager to observe whether there are abnormal programs running in the background of the failed machine, and try to close the program to keep only the most basic background programs.

C. Pay attention to check whether there is a shared DLL file in the faulty machine. The problem can be solved by changing the installation order or installation directory.

5) Check whether the hardware settings are incorrect

A. First, check whether the CMOS settings are correct, and the default values can be restored;

B. In the device manager, check whether the hardware is normal and whether there are conflicts between interrupts. If there are conflicts, adjust the system resources (for some hardware, read the instructions and set the hardware correctly according to the instructions);

C. Delete the hardware driver in the Device Manager, reinstall the driver (it is better to install the correct version of the driver), and check whether the hardware driver returns to normal;

D. Run the hardware detection program, such as AMI, to detect whether the hardware is faulty;

E. Under the condition of minimum software system, update the hardware drive again and observe whether the fault disappears.

6) Check whether it is a compatibility problem

A. When encountering compatibility problems, check the specifications and standards of the hardware (as when using multiple memories, check whether the memories are of the same manufacturer, the same specification, the same capacity, and the same batch of memory particles), and whether they can be used together.

B. Read the manual or look up relevant information on the website to check the software requirements required for the normal use of the user's hardware, whether the current software environment meets the requirements, and whether the software and hardware support each other.

C. Check whether the user's system resources conflict in the Device Manager. If there is a conflict, manually adjust the system source.

D. Check whether the hardware drivers of the user's machine are installed correctly in the device manager, and update the appropriate version of the device drivers (for example, some graphics cards use WIN2000 or WINXP's own public drivers, which may cause some large-scale 3D games to fail to run);

E. Check the maintenance BOM, remove non Lenovo hardware, and check whether the system can work normally. If it can work normally, it is recommended that the user replace the hardware added by himself or search for hardware related information to solve the problem.

7) Check whether it is caused by network failure

A. When the machine is connected to the network, and there is a crash, slow operation, blue screen and other failures, you should first shut down the network, isolate it from the network environment, and observe whether the failure disappears. If the failure disappears, it is a network problem that causes the failure.

B. The fault is caused by the network problem. Refer to the network part for the judgment and solution steps.

8) Check whether it is caused by poor hardware performance or damage

A. Use the corresponding hardware detection program to check whether there is any hardware fault, and if there is, use the replacement method to eliminate the corresponding hardware;

B. Use the replacement method to check the hardware failure that cannot be determined by the detection program.

Chapter VII LAN Faults

1、 Example of definition

This kind of fault mainly involves the fault in the network environment such as LAN broadband network.

2、 Possible symptoms

1. The network card does not work, and the indicator status is incorrect;

2. The network cannot be connected or only a few machines cannot access the Internet, Ping can be connected but cannot connect to the network, and the network transmission speed is slow;

3. Data transmission error, network application error or crash;

4. The network works normally, but the network cannot be used in an application;

5. You can only see yourself or individual computers;

6. No disk station can not access the Internet or error is reported during startup;

7. The network device installation is abnormal.

8. The network is not always connected.

3、 Possible components

Network card, switch (including HUB, router, etc.), network cable, motherboard, hard disk, power supply, and other related parts.

4、 Key points/sequence of judgment

1. Preparation before maintenance

1) Available network cable (direct connection and ordinary network cable, line sequence in line with international standards);

2) If possible, the Internet cable connection checker shall be provided.

2. Environmental inspection

1) Power connection check:

A. Whether the connection definition of mains power is correct;

B. Whether there is ground wire;

C. Whether all devices on the network (such as HUB, switch, etc.) have been powered on.

2) Network cable connection inspection:

A. Whether the sequence of network cable connecting lines matches the requirements of network connection (such as direct connection and ordinary network cable);

B. Whether the connectivity of the network cable is normal, check whether the network cable is damaged or excessively twisted;

C. Whether the length of the network cable is too long (for example, the length of Category 5 twisted pair exceeds 100 meters as required by the technical specifications);

D. Network cable connector - whether the crystal head is intact and oxidized;

E. Whether the network card interface is intact. Re plug the network cable and check whether the connection between the network cable and the network card is loose;

F. Whether there is terminator according to the cable requirements, and whether the terminator is normal.

3) Appearance and peripheral inspection of network equipment:

A. Whether the network card indicator is on after power on;

B. After the network cable interface of HUB and other equipment is connected to the terminal or server, if the terminal or server is started and configured normally, its indicator light will be on (note whether the color of the indicator light is normal, refer to the equipment manual). If the indicator light is not on, it indicates that the equipment is faulty;

C. Whether the network card parts are inserted in place without lifting, and whether the gold fingers on the network card are oxidized;

D. Whether there is interference around the network cable or switch.

4) Appearance inspection of host:

A. Check whether there is foreign matter in the chassis causing short circuit;

B. Whether there is too much dust in the case, and if so, clean the dust;

C. Whether the components on the mainboard and network card are deformed or discolored;

D. After power on, pay attention to whether components, components and other equipment have peculiar smell, abnormal temperature and other phenomena.

5) Other aspects:

A. Under UNIX, it is necessary to distinguish whether the terminal crashes or the server crashes

　 3. Key points of fault judgment

1) Seek the cooperation of user network management.

First, try to contact the network management to get the cooperation of the network management.

2) Network environment check:

A. Check the compatibility between the network card and the switch for failures such as dropped lines and packet loss;

B. The network connection is normal, but the domain login cannot be performed. Check from the following points:

a) Whether the specified domain name exists or works;

b) Whether the terminal is allowed to log in to the domain and whether the computer name is registered in the domain according to the requirements of the server and operating system (for example, if the WINS resolution service and DNS service are enabled on the server side, the WINXP HOME version cannot log in to the domain);

c) Check whether the protocol used is correct;

C. Check whether a firewall is installed and whether access is authorized;

D. If necessary, use a direct connection to only connect two machines to check whether they can be connected to the network in a peer-to-peer environment (this can eliminate the impact of various environmental factors on the network).

3) Network adapter driver and attribute check:

A. Whether the driver is correct and appropriate. It is recommended that the network card device be automatically identified by the system, and use drivers that match and update the operating system as much as possible (only the old ISA network card can be installed manually). When installing drivers, if necessary, turn off the programs loaded and running during startup, and then install them;

B. If the network card does not work normally in a certain network environment, the network speed can be adjusted. For example, for a 10/100Mbps network card, if the network card works abnormally in a 10Mbps network environment, the network card should be specially designated to work at a speed of 10Mbps;

C. Check the network communication mode, such as whether it is full duplex.

4) Network protocol check:

A. Check whether the protocol settings in the network are correct (no matter which protocol is used, the protocol used by the machines in the network must be consistent). Whether there are duplicate computer names in the network;

B. If you cannot see yourself or other computers, first press F5 to refresh several times to check whether the file and print sharing service is installed and enabled, and whether the NETBEUI protocol is added (if there is a WINS server in the network environment, you do not need to add it, if not, you need to add it);

C. If you can ping the network, but cannot access other terminals or servers in the network neighborhood, you can use ipconfig/all (in command line mode), netstat and other commands to view specific information, check the settings of network attributes, such as domain, workgroup, and make corresponding changes;

D. The TCP/IP protocol utility ping command can be used to check the operation of the network. This requires the maintenance personnel to understand the TCP/IP protocol (order: PING 127.0.0.1, local IP, local network segment IP, gateway, DNS, etc.);

E. If PING fails, you can try to delete all adapters and protocols in the network properties and reinstall them after restarting;

F. By executing the tracert<target IP address>command, check which network segment the IP packet is in error;

5) System settings and application check:

A. Check whether the network cards listed in the resource list are listed (except for non PNP network cards) after the self inspection of the machine is completed, and whether the resources used are shared with other devices;

B. Check whether there are other devices in the system that conflict with the resources used by the network card. If there are, change the installation location between the devices or manually change the conflicting resources. For the network card of ISA bus, it may be necessary to turn off the PnP attribute of the interrupt it occupies in CMOS, and the resources it uses should not be shared with other devices generally. Older PCI devices should not share resources with other devices;

C. Check whether there is virus in the system;

D. If a particular application does not work properly when using the network, check whether the CMOS settings are correct, and focus on whether the driver of the network card matches it. If necessary, close other running applications and programs loaded during startup to see whether they work normally, or compare with the machine that can run the application normally, Check whether the configuration is different;

E. By reinstalling the system, check whether the network is not working properly due to system reasons.

6) Hardware check:

A. Check whether the network card is in good condition by using the program provided with the network card and the short circuit ring of the network card;

B. If it is still abnormal after replacing the network card, you can replace the motherboard. If the replacement of the motherboard still fails, you can worry about replacing another model of network card;

7) For a non disk station, check the following points:

A. Whether boot from network is allowed in BIOS, it is better to disable floppy drive in BIOS and change "Report No FDD For Win 95" from Yes to No (or vice versa. This is related to the setting of floppy drive)

B. For the ISA network card, the BIOS should be set so that the default starting address of the BOOT ROM is D800H or C800H, and the I/O is 300H (for example, the default setting of some network cards is C800H, which is easy to conflict with the address resources occupied by the AGP graphics card and other computers, resulting in installation failure).;

C. If the above operations are invalid, modify the sound card on some mainboards and shielded boards as needed.

D. The workstation protocol must be consistent with the server protocol;

E. When there are multiple servers, you must specify the first response server.

For wireless networks, pay special attention to:

A. Check whether the effective distance between the two terminals is too large, and whether there is an insulator in the middle;

B. Whether the frequency channels used in the peer-to-peer network are consistent;

C. In the AP environment, the network ESSID of the terminal must be consistent with that of the AP;

D. Check whether the keys of the network card and the AP match.

5、 Judgment process of this type of fault

See Appendix I (VII).

6、 Case

Case 1:

Problem description: The network card does not work, and the indicator light status is incorrect;

Solution: First, observe whether there is a network card in the system device manager. If there is no network card, replace the network card or reseat the network card for testing, and check whether there is rust on the golden finger. If there is, clean it with an eraser for testing.

　 Case 2:

Problem description: In the LAN, only a few machines can be connected to the network, and most of them cannot exchange visits. The network card light is on, and the HUB light is flashing

Solution: To see this situation, we should analyze it from two aspects: soft and hard. First:

a. In terms of software, the latest version of KV3000 was used to check and kill viruses, and no virus was found, thus eliminating the possibility of virus interference. In terms of network, NetBEUI, IPX/SPX and TCP/IP protocols are installed. The drivers of the network card are also installed correctly. No conflicts are found in the device management, and protocol binding is performed. File and printer sharing, workgroup name and computer name are set. It should be said that there are no problems with the network protocol and shared resource settings, and software errors can be ruled out.

b. From the perspective of hardware, there are roughly four possibilities: first, the network cable is open circuit, unable to form a signal loop; The second is whether the network cable sequence is correct; Third, the network cable used to connect the hub and the computer is too long, more than 100 meters; The four hub ports are faulty. The four possibilities are excluded one by one. Use a line measuring tool or a multimeter to measure the network cable. It is found that the network cable is well connected and there is no open circuit. Through visual inspection, the length of the network cable for connection cannot exceed 100 meters. Connect several computers connected to the network to the socket on the hub and switch them to the suspected damaged hub port. These computers are still interconnected, indicating that the hub port is not damaged.

c. Through the inspection of the network cable sequence, it is found that the user's line sequence is 1, 2, 3, and 4. This is where the problem lies, because the correct connection of the RJ45 plug should use 1, 2, 3, and 6, where 1, 2 are a pair of lines, 3, and 6 are a pair of lines, and the other four lines are undefined. The problem was found. Just redo the network cable head for the user. The network is normal after insertion.

　 Case 3:

Problem description: The brain can only see itself in the "network neighborhood", but can't see other computers, so it can't use shared resources and shared printers on other computers

Solution: Use the ping command to ping the local IP address or hostname, and check whether the network card and IP network protocol are installed properly. If you can ping, it means that the network card and network protocol settings of the computer are OK. The problem is the connection between the computer and the network. Therefore, you should check the status of the network cable and the Hub and the Hub interface. If you cannot ping, it only indicates that there is a problem with the TCP/IP protocol. Reset the network protocol. The NetBEUI protocol can be used for less than 10 machines that do not access the Internet. If you access the Internet, the TCP/IP protocol will be used. No matter which protocol you use, you must ensure that the protocols used by the machines in the network are the same.

　 Case 4:

Problem description: No disk station can not access the Internet or error is reported during startup;

Solution:

The NOVELL diskless workstation cannot log in to the server normally in the following cases:

a. "Error opening boot disk image file" OR "Unable to open image file" appears on the workstation screen

This may be a connection to a server that does not contain a remote boot image file. Copy the boot image file to the Login directory of this server; If a multi remote boot image file is used, check whether the workstation is correctly set in Bootconf.sys, and ensure that the network address and node address are correct. If all the above are correct, then there may be a problem with the remote boot image file. You can test whether the floppy disk that generates the boot image file can start the disk workstation normally. If not, run the RPLFIX utility.

b. "Error finding server" appears on the workstation screen

On the premise of ensuring that the hardware circuit is connected properly, check whether the "Ethernet_802.3" frame type is installed on the server, and whether the net.cfg of the remote boot image file contains Ethernet_802.3. This is the old IPX chip mentioned above, which does not support Ethernet-802.2 frames. Remake the boot image file according to the corresponding frame type.

c. The workstation hangs when loading the network card drive from the remote boot image file, and the screen displays the following similar information: Ethernet card is properly installed or net connected the network

This is because when the old IPX chip mentioned above is used above Netware 4. X, there is no RPLODI.com line in the remote boot image file or there is no RPLODI.com line in the ISL.com line in the batch file of the remote boot image file.

d. The workstation displays "Loading MS-DOS" and hangs

This is because the remote boot image file uses DOS 5.0 or above. Run the RPLFIX utility on the file of the remote boot image.

e. "Batch file missing" appears on the screen

This message appears because autoexec.bat or other batch files (used for batch processing of multiple remote boot images) do not exist in the LOGIN directory and the user login directory at the same time.

Chapter 8 Internet Failures

1、 Example of definition

It mainly refers to software and hardware failures related to browsing the Internet. For example: unable to dial, unable to browse the web page, etc.

2、 Possible symptoms

1. No dialing, no dial tone, noisy dialing, and offline Internet access;

2. Slow internet access, individual web pages cannot be browsed;

3. Crash, blue screen error, etc. when surfing the Internet;

4. Can receive email but cannot send email;

5. Abnormal installation of network equipment;

6. Other communication equipment connected to the modem is damaged, or vice versa.

3、 Caisongning possibly involved

Modem, telephone, telephone line, office terminal. Other types are the same as "LAN failures".

4、 Key points/sequence of judgment

1. Environmental inspection

1) Perimeter and appearance inspection:

A. Whether the connection definition of mains power is correct and whether there is a ground wire;

B. Whether there are transformers or other electrical equipment that may cause interference near the external MODEM;

C. Whether the phone has anti-theft call function, and whether it is equipped with IP phone dialer, fax machine and other external equipment. Whether these external devices are connected correctly and work normally (in case of independent operation and connection);

D. Check whether there is much dust in the case, whether there is foreign matter causing short circuit, and whether the plug collector is inserted in place and not cocked up;

　E. Whether the components on the mainboard, MODEM or broadband network card are deformed or discolored;

F. Whether the network card interface is in good contact;

G. After power on, pay attention to whether there is odor, abnormal temperature and other phenomena in the collector, components and other equipment.

2) Signal line connection:

A. Whether the telephone line is correctly connected, whether the connected telephone line is normal, whether the user's telephone is an extension, and whether there is a call reminder;

B. Are there any restrictions on the number dialed;

C. Whether the definition of the network cable for broadband Internet access is correct and whether it can be connected. If possible, change the environment of the machine (such as going to a neighbor's home or returning to the station) and then test it to verify whether it is a connection problem;

2. Key points for fault judgment

1) MODEM configuration check:

A. Check whether the settings in CMOS are correct. Whether the MODEM equipment is recognized by the system;

B. Add MODEM to the minimum system of software, and check whether the fault phenomenon disappears. If it disappears. Is caused by incompatibility between hardware or resource conflict;

C. Check whether the MODEM driver is correct and whether there are resource conflicts in the device manager. Whether the protocols supported by MODEM are incompatible with the office end. When the drive is not correct, it may lead to Internet drop, slow Internet access and other phenomena. Delete the original MODEM driver (it is better to delete MODEM in the control panel - Modem), and reinstall the MODEM driver after installing the mainboard driver;

D. Whether the MODEM device attribute settings are correct (such as the connection speed used).

2) Dialer/dialing process check:

A. Check whether the dial-up program used by the user is third-party software. It is recommended to use a new dial-up connection to dial the Internet (it is better to not use the user's account). Check whether it can dial and whether an error is reported;

B. Pay attention to the error message, and preliminarily determine the cause of the fault (such as 680 error, no dial tone, 678 error, no response from the remote server, etc.);

C. Whether the user has access to the Internet network.

3) Network attribute and protocol check:

A. If the service provider dials up the Internet, the IP address and other parameters should not be set except that the IP protocol must be installed. Other internet access modes shall be set as required;

B. Whether the dial-up protocol used is consistent with the requirements of the service provider (such as PPP protocol).

4) IE check:

A. For Windows 98, if IE fails, it is recommended to upgrade IE to 5.5 or patch it;

B. Check whether IE attribute settings are correct and whether IE is modified due to going to a website. If there are too many temporary files, you may not be able to browse the web page after surfing the Internet (you can delete temporary files in IE properties, etc. See the method of deletion later in this chapter). Whether you can't browse the web page because you haven't installed the necessary plug-ins for some websites. Check the security level settings in IE and the hierarchical check settings, and restore them to the default values;

C. Check whether the system is modified (such as the registry is disabled) due to some websites;

D. Check whether the user's software environment is difficult to browse due to anti-virus, firewall and other software or incorrect settings.

5) System check:

A. Check whether there is virus in the system;

B. In MSCONFIG, close all programs loaded at startup and all running programs. Prevent the inability to access the Internet due to software conflicts;

C. If necessary, reinstall the operating system for testing.

6) Hardware check:

A. Replace the slot where the MODEM is located, re detect the MODEM and install the driver. If the Internet is unavailable, replace the MODEM test;

B. If it is impossible to dial after a thunderstorm, in addition to checking whether the cable and other equipment on it are damaged, check whether the MODEM is damaged;

C. If the Internet is not available, check other hardware;

7) In case of failure of broadband Internet access, check:

A. Check whether the network card driver is installed correctly;

B. Use closed loop to test whether the network card is normal;

C. Set the dialing attribute correctly according to the local actual situation, reinstall the dialing software according to the broadband Internet access instructions, and set various settings;

D. Replace the network card of different models for testing, and eliminate the incompatibility;

E. Contact the telecommunications office or the community network management to check the network environment or connection equipment;

F. For automatic Internet access, the proxy server should not be set. For early broadband networks, IP should be set.

5、 Judgment process of this type of fault

See Appendix I (VIII).

6、 Case

Case 1:

Problem description:

A client's machine uses 98 operating system. When dialling to access the Internet, he found that the web page could not be opened, but there was indeed a link icon in the lower right foot. He found that there was no network traffic, but after several more dials, the problem was solved. The problem reappeared irregularly. The client needs to explain the reason and prove that it was not a problem of the machine.

Solution: The customer asked for a reasonable explanation, because the machine is not unable to access the Internet. To learn this, we should worry about the software. We can't change the hardware at the beginning, which makes the customer feel bad.

The machine can dial normally, which means that the modem hardware and driver of the machine are OK, but after careful observation, it is found that the network traffic is 0, which means that the machine is not on the network, and the link symbol at the lower right foot may be a fake. Using the ipconfig/all command, it is found that the machine has not obtained an IP address. Why is this phenomenon? I think that the network traffic is related to the telecom access end, Repeated tests of dial-up Internet access showed that if you get an IP address after dialing, you can definitely access the Internet. If you don't get an IP address, you can't open the web page. After seeing this phenomenon, the customer basically accepted my statement, and hoped to reinstall the operating system to see if it could be solved. After reinstalling the 98 operating system, the problem remained, The customer has thought that the machine is OK. In the new 98, I used another way for the customer to test, that is, to dial with the super terminal inside the 98. The reason is that the super terminal can see the whole process of dialing, and whether the IP address can be obtained. After using the super terminal to dial 5-6 times, I found that the IP address was not obtained once. So far, the customer is completely convinced, The real reason lies in the office end of the telecommunications, not in the machine itself.

Case 2:

Problem description: The operating system installed on the client machine is 98. In addition to installing Modem, a network card is added. The client machine usually uses the LAN on the network card. The network card uses DHCP to obtain the IP address, but it cannot dial to access the Internet when dialing, but there is a dial tone. The client requires a thorough solution.

Solution: The customer has used Modem to dial up the Internet before, but now they can't use it. They are excited. In addition to the solution, they also need full communication, so the process of processing is very important.

During the test, I found that the fault recurred. After communicating with the customer, I found that the customer could indeed dial in before. Recently, due to the installation of a network card, the LAN could be connected, and dialing was not possible. After communicating with the customer, I think it is not the problem of the machine itself, but also related to the setting and operating system itself, This problem is not found on other machines under 2000. First, I screened the network card, and then tested the dial-up connection. I found that the failure disappeared. Is it related to the network card? Open the network card, and found that the dial-up connection was possible. The problem was solved! What's the matter? After restarting, it is found that the LAN is connected to the LAN and the dialing is abnormal again. The fault reappears. If the super terminal is used to dial, it is found that the IP address cannot be obtained. OK, the problem is found, but what causes the IP address cannot be obtained?

Songzhulai is related to the operating system. Because there is no such problem under 2000, it should be related to the network card under 98. Because this LAN uses DHCP mode, I use winipcfg to realse the network card IP and dial again to solve the problem. Finally, I found the problem. After repeatedly starting and releasing the network card IP, the dialing was normal. After communicating with Microsoft engineers, I determined that 95 and 98 did have this problem, However, the problem has been solved under 2000, so far the problem has been successfully solved, and the customer said that he was very satisfied.

Case 3:

Problem description: The customer bought a Modem, with which he can dial 163/169 to access the Internet, but he cannot dial the company's LAN to send and receive emails. The customer hopes to help solve the problem, although the customer's Modem is not standard.

Solution: The customer is quite familiar with the computer, so he just asked us to help solve the problem and find out the real reason. So when dealing with this problem, try not to open the chassis and replace the motherboard. The key is to worry about compatibility.

Because it can be dialed to 163, but cannot be dialed to the company's network, I focus on the model and protocol of the customer's Modem. The customer's Modem is a domestic Tongwei product, which supports the V.90 protocol. The customer's Modem is a 3COM product in the United States, which also supports the V.90 protocol. First, dial to the company with a super terminal, and the dial tone will be automatically disconnected 2 seconds after the dial tone appears, The failure to get the IP address indicates that there is a compatibility problem between the two modems. There is a problem during the handshake phase. After explaining clearly to the customer, the customer borrowed a 3COM modem from his company. First, the dial-up network was used to test that everything was normal, and then the super terminal test found that everything was normal. The customer was very satisfied and thought that our test method was very convincing.

Attachment: The following methods can be used to delete temporary files in IE:

1. Open IE browser, delete temporary files and clear history in Tools - Internet option. (If IE cannot be opened, you can select "Start Internet Explorer every time" in this setting, or increase the disk space used by temporary Internet folders;

2. Select Clear in Start Settings Taskbar and Start Menu Start Menu Programs;

3. Delete the history in the c: windowsthistory directory;

4. Delete all files in c: windowsTemporary Internet Files;

5. Use third-party software such as the network name to clear.

Chapter 9 Port and Peripheral Failures

1、 Example of definition

This kind of fault mainly involves the faults of serial and parallel ports, USB ports, keyboards, mice and other devices.

2、 Possible symptoms

1. The keyboard does not work properly, and the function keys do not work;

2. The mouse does not work properly;

3. Cannot print or cannot print under certain operating system;

4. External equipment does not work normally;

5. Serial port communication error (such as: transmission data error, data loss, serial device recognition failure, etc.);

6. The use of USB devices is abnormal (for example, the USB hard disk cannot be moved, and multiple USB devices cannot be connected);

3、 Caisongning possibly involved

Settings in the acquisition device (such as motherboard), power supply, connecting cable and BIOS with corresponding ports.

4、 Key points/sequence of judgment

1. Preparation before maintenance

1) Prepare the short circuit ring test tool of the corresponding port;

2) Prepare test procedures QA, AMI, etc. - these procedures are required to run under DOS;

3) Prepare cables for corresponding ports according to the resources in the station, such as parallel port, printer cable, serial port cable, USB cable, etc.

2. Environmental inspection

1) Connection and appearance inspection:

A. Whether the equipment data cable interface is well connected with the host, and whether the pins are bent, missing, short circuited, etc;

B. For some brands of USB hard disks, users should be informed that it is better to use an external power supply to make them work better;

C. Whether the connection port and relevant control circuit are deformed or discolored;

D. Whether the cable used for connection is matched with the equipment to be connected (for example, if two machines are connected through the serial port, the connection line of the air conditioner demodulator should be used instead of the MODEM line).

2) Peripheral inspection:

A. Whether the power adapter of the external equipment matches the equipment;

B. Check whether the external equipment can be powered on (including its own power supply and power taken from the host signal port);

C. Check whether it can work normally under pure DOS. If it does not work, check the cable or replace the peripheral and motherboard;

D. If the external equipment has the function of self inspection, check whether it is intact in advance; External equipment can also be connected to other operating machines for detection.

3. Key points for fault judgment

1) Simplify the system as much as possible, and remove irrelevant peripherals first;

2) Port setting check (BIOS and operating system):

A. Check whether the BIOS setting of the motherboard is correct, whether the port is open, and whether the working mode is correct;

B. Test whether there are compatibility problems by updating BIOS, replacing motherboards of different brands or chipsets;

C. Check whether the corresponding ports in the system have resource conflicts. Whether the peripheral driver connected to the port has been installed, and whether its device properties are compatible with the external device. If the settings are correct, check the corresponding hardware - motherboard, etc;

D. Check whether the port can be used in DOS environment by connecting a peripheral or using the port detection tool described below;

E. For serial port, parallel port and other ports, the special short circuit ring of the corresponding port must be used, and the corresponding detection program (AMI is recommended) must be used for inspection. If an error is detected, replace the corresponding hardware;

F. Check whether there are improper settings in some application software, causing some peripherals to work abnormally in this application. For example, in some applications, improper hotkey combinations are set so that some keys cannot work properly.

3) Device and driver check:

A. When reinstalling the driver, it is preferred to use the unloading program provided with the device driver, such as the Z32 printer;

B. Check whether the device software setting corresponds to the actual port used, for example, USB printer needs to set USB port output;

C. The installation sequence of USB device, driver and application software shall strictly follow the instructions;

D. It is better to use a newer version of the peripheral driver, which can be upgraded on the manufacturer's website.

Chapter 10 Audio and Video Faults

1、 Example of definition

Software and hardware failures related to multimedia playing and production.

2、 Possible symptoms

1. Error or crash when playing CD, VCD or DVD;

2. When playing multimedia software, there is no image or sound;

3. There is noise when playing the sound, which is abnormal and silent;

4. The sound is too small or too loud and cannot be adjusted;

5. The recording that cannot be recorded or played is noisy or low in sound;

6. Equipment installation is abnormal.

3、 Caisongning possibly involved

Audio and video boards or devices, motherboard, memory, optical drive, disk media, chassis, etc.

4、 Key points/sequence of judgment

1. Preparation before maintenance

1) In addition to necessary maintenance tools, the latest device drivers, patches, motherboard BIOS, the latest DirectX, standard format audio files (CD, WAV files), and video files (VCD, DVD) should be prepared;

2) Be familiar with various settings of multimedia application software, such as the settings of sound properties under Windows, the settings of application software attached to sound card/video card, and the settings of video box/card application software;

3) Learn about the user's information specifically, mainly about whether new hardware, software, and system reinstallation (including one click recovery) have been installed before the failure.

　 2. Environmental inspection

1) Check whether the mains voltage is within the allowable range (220V ± 10%);

2) Check whether the power supply and data cable of the equipment are connected correctly, and whether the plug is fully plugged, such as the audio/video connection of the speaker and video box; Whether the switch is open; Whether the volume of speakers is adjusted to an appropriate level;

3) Observe whether the user's operation method is correct;

4) Check the surrounding environment for high-power interference devices, such as air conditioners, rear projection, large screen color TV, refrigerators and other high-power appliances. If any, it shall be kept at a distance (more than 50 cm);

5) Check whether the BIOS settings on the motherboard have been adjusted. Restore the settings to the factory state first, especially check whether the CPU and memory have been overclocked.

　 3. Key points for fault judgment

1) For sound faults (silence, noise, mono, etc.), first confirm whether the speaker is faulty. Method: connect the speaker to other sound sources (such as recorder, walkman) to detect whether the sound output is normal, and then determine whether the speaker is faulty;

2) Check whether the multimedia function does not work properly because the corresponding plug-in or patch is not installed;

3) For multimedia playback and production failures, if the failure occurs in different players and plays different multimedia files, check the relevant system settings (such as sound settings, CD drive attribute settings, sound card drivers and settings). Even check whether the relevant hardware is faulty;

4) If the fault occurs only in a specific player and works normally in other players, the player software with the problem should be checked to see whether the software settings are correct and whether it can support the format of the played file. After reinstalling or upgrading the software, check whether the fault is eliminated;

5) If the fault occurs when reinstalling the system, replacing the board, recovering the system with the system recovery disk, or using the one button recovery, first check the board drive installation, such as whether the drive matches the corresponding equipment;

6) For faults related to video input and output, first check whether the video application software is set correctly in the signal format, that is, it should use the same format as the signal source (such as cable TV signal) and signal terminal (TV, etc.). PAL system is widely used in China;

7) When importing video, pay attention to whether the audio input settings of the video import software and the sound card are consistent. For example, if the audio input in the software is MIC, the audio cable is connected to the MIC port of the sound card, and the audio input of the sound card is set to MIC;

In case of failure in reading multimedia files from the optical drive only, such as slow and discontinuous DVD/VCD playback, check the transmission mode of the optical drive first and set it to "DMA" mode;

9) Check whether there is third-party software that interferes with the normal use of the audio and video functions of the system. In addition, anti-virus software will cause slow and inconsistent DVD/VCD playback (such as Rising, which should be turned off);

10) Software inspection

A. Check whether there is virus in the system;

B. Sound/audio attribute setting: volume setting, whether to use digital audio, etc;

C. Video settings: resolution and color depth in video properties;

D. Check the version of DirectX and install the latest DirectX. At the same time, use the Dxdiag.exe program provided by it to check the sound card equipment

E. Device driver inspection: In the "System Device Management" under Windows, check whether the multimedia related devices (video card, sound card, video card, etc.) are normal, that is, there should be no "?" or "!" signs, and the device driver files should be complete. If necessary, the driver can be uninstalled and reinstalled or upgraded. For the sound card equipment that must be manually installed as indicated in the instruction manual, it should be deleted or directly overwritten as required (at this time, the system should not automatically search, but manually select from the equipment list);

F. If the user has reinstalled the system, it may not follow the correct steps when installing the drive (such as restarting), which causes the system display device to be normal, but the actual drive does not work correctly. At this time, the driver should be reinstalled for the user. The method can be the same as above;

G. After recovering the system with the system recovery disk, or using the one button recovery, it sometimes appears that the device identified by the system is not the device actually used by the user, and no error is reported in the "System Device Management" under Windows. At this time, you must carefully check whether the device name is consistent with the actual device, If it is inconsistent, reinstall the driver (for example, the sound card chip is inconsistent with the original one after replacing the replaceable motherboard);

H. Re installing the driver still cannot eliminate the fault. You should worry about whether there is an updated driver version, and you should upgrade the driver or install patches.

11) Hardware inspection

A. Use the memory detection program to detect whether the memory part is faulty. Worried about hardware includes motherboard and memory;

B. First, the replacement method is used to check the boards and equipment directly related to the fault. Sound problems: sound card, speaker, audio interface jumper on the motherboard; Display problems: video card; Video input and output problems: video box/card;

C. When a failure occurs when reading multimedia files from the optical drive only, and the software setting is invalid, use the replacement method to determine whether the optical drive is faulty;

D. For noise problems, check whether the audio cable of the optical drive is correctly installed, whether there is a problem with the speaker itself, whether there is a fault with the speaker power adapter, and other matching problems;

E. Use disk fault judgment method to detect whether the hard disk is faulty;

F. Use the replacement method to determine whether the CPU is faulty;

G. Use the replacement method to determine whether the motherboard is faulty.

5、 Judgment process of this type of fault

See Appendix I (X).

6、 Case

Case 1:

Problem description: The user reported that the Tongxi E5000 computer was installed with the Windows XP system. When users play audio and video files, such as VCD, CD, MP3, etc., the "Zizi" noise in the speaker is obvious.

Solution:

Generally, when you see such problems, you always think of the problem of the speaker or the sound card on the motherboard first. However, the engineer replaced the speaker and motherboard successively, but the fault still remained. At this time, the maintenance is in trouble.

In fact, as long as you carefully observe and think about sadness, and observe in the way of soft first and hard second, the problem should be solved quickly. In this case, because the machine itself is a DOS system, the Windows XP is installed by the user, and the sound card driver is also recognized by Windows XP. It is the drive provided by XP that has a problem, causing the problem of the user's repair. As long as you install the corresponding driver in the accompanying drive CD, the problem will be solved.

Case 2:

Problem description: The user purchased the Future Pioneer 722 machine and installed WINDOWS 98 by himself. He found that there was no sound when playing the CD. In the sound control, the CD control has been turned on, and the volume has been adjusted to the maximum.

Solution: First of all, we need to know this. The audio cable between the CD drive and the sound card is no longer configured for operating the factory pre installed Windows XP machine. When playing CDs, the digital audio function provided by XP itself is used to play directly. Windows 98 does not have the function of digital audio. Knowing this, the answer to the user's question will be clear.

Tell the user that the standard configuration of the machine uses the digital audio function of WINDOWS XP to play CDs, so the machine is not configured with an optical drive audio cable. Windows 98 does not support the digital audio function, so this problem will occur. It is recommended that you use the Windows XP operating system or add an audio cable yourself.

It is easy to see from this case that understanding and mastering the product configuration and technical specifications is an important guarantee for us to solve user problems.

Chapter XI Compatibility or Cooperation Failure

1、 Example of definition

This kind of fault is mainly caused by the user adding third-party software and hardware equipment.

This kind of fault has been partially mentioned in the previous types of faults. Therefore, some fault phenomena may be similar to the fault diagnosis described above. Please refer to Sadness.

2、 Possible symptoms

1. After the user's equipment or application is installed, the system operation is unstable, such as crash or restart;

2. The equipment installed by the user cannot work normally;

3. The application developed by the user does not work properly;

4. The configuration required by the user cannot be satisfied on the operating machine (such as the need to add large capacity memory, the need for multiple serial ports, etc.).

3、 Caisongning possibly involved

All possible mining chants or software. But the most influential third party applications are the mainboard, CPU, memory, display card, and peripherals of new interfaces.

4、 Key points/sequence of judgment

1. Environmental inspection

1) Check the manufacturing process of external equipment boards and cards. For boards or equipment with rough process, it is easy to cause black screen, power failure and unstable operation;

2) Check whether the added memory module is the same model as the original memory module. First, different models may cause compatibility problems, which may lead to unstable operation, crash, etc; The other is to pay attention to modifying the settings in the BIOS;

3) Whether the technical specifications of the updated or added Caixining, such as CPU and hard disk, are compatible with the rest of Caixining. The new or old Caixunning will be incompatible with the original configuration. For example, the old collector does not support power management, so that when the system is running, the collector will not work normally, or the whole system will not work normally.

2. Key points for fault judgment

1) After starting up, first check whether the newly updated or added acquisition formula can appear in the configuration list that appears before the system is started. If not, check its installation and technical specifications;

2) In case of no display, unstable operation or crash, the updated or additional acquisition equipment or devices shall be removed first to see whether the system has returned to normal working state, and the technical manuals of new equipment and acquisition equipment shall be carefully read to understand the installation and configuration methods;

3) If the additional equipment cannot be installed normally, check its technical manual for correct installation methods, technical requirements, etc., and try to use the latest version of the driver. If the problem cannot be solved, check the working condition of the original system of the external equipment;

4) Check whether resources cannot be shared between the newly added or updated Caixining and the original Caixining, that is, turn off the corresponding Caixining resources to check whether the fault disappears. If it cannot be turned off, try to change the installed slot position or change the resource formula in the BIOS;

5) Check whether the compatibility problem is caused by the BIOS. This can be checked by updating the BIOS (note that it is not necessarily the latest version or higher version, you can lower the version check);

6) Check whether the jumper settings on the added Caisongning are appropriate, and make necessary setting modifications;

7) For older boards or software, attention should be paid to whether the operation is abnormal due to speed mismatch;

Check whether the fault disappears by changing the settings or services in the system. Such as power management service, equipment parameter modification, etc;

9) Check whether the original software and hardware have poor performance, that is, by replacing the hardware or shielding the original software.