Basic principles and methods of computer maintenance

Chapter 1 basic principles and methods of computer maintenance

The principles and methods described here are the basis for classification judgment in the second part and must be followed seriously.

§ 1. 1 Basic Principles for computer maintenance:

1. The maintenance judgment should start with the simplest thing

Simple things refer to observation on the one hand and a simple environment on the other.

The simple thing is to observe, which includes:

1. computer environment: location, power supply, connection, other equipment, temperature and humidity;

2. Computer symptoms, displayed content, and their similarities and differences with normal circumstances;

3. computer environment: dust, connection, device color, component shape, indicator status, etc;

4. Software and Hardware configuration of the Computer-what kind of hardware is installed and the usage of resources; what kind of application software is used for the xx system; set the driver version of the hardware.

A simple environment includes:

1. The minimum system to be mentioned in the future;

2. Only basic running parts/software and suspected faulty parts/software are included in the judgment environment;

3. Add your applications (hardware and software) to a clean SysTem for Analysis and judgment.

Starting from a simple task is conducive to concentrated energy and Fault Judgment and locating. It must be noted that judgment and repair can be performed only after careful observation.

2. Based on the observed phenomenon, you should "first think about it and then do it"

First, I want to do it later, including the following aspects:

First, first think about how to do it, where to start, and then practice. It can also be said that it is to analyze and judge before maintenance.

Second, for the observed phenomenon, check the relevant information as much as possible to see if there are any corresponding technical requirements, usage characteristics, and so on. Then, based on the information, combine the content to be discussed below, and then start to repair.

Finally, in the process of analysis and judgment, you should make judgments based on your existing knowledge and experience, consult with experienced colleagues or technical support engineers for help.

3. In most computer service judgments, the software must be soft and hard:

That is to say, from the entire service judgment process, we always judge whether the fault is software fault first, and first check the software problem. When the software environment is normal, if the fault cannot disappear, check the hardware.

4. In the maintenance process, we should distinguish the primary and secondary, that is, "grasp the main contradictions".

When a fault occurs again, you may sometimes see more than one fault on a faulty machine, but two or more faults (for example, no fault occurs during the startup process, however, the machine is also starting, and after the machine is started, there will be crashes.) for the time being, we should first judge and maintain the main fault phenomena. After the repair, we should repair secondary faults, sometimes secondary failures do not require repair.

§ 1. 2 basic computer repair methods

I. Observation

Observation is the first method in the Service judgment process. It runs through the whole maintenance process. Observation should be both serious and comprehensive. The following content should be observed:

1. surrounding environment;

2. hardware environment. Including plug, seat and slot;

3. software environment;

4. User xx's habits and processes

Ii. Minimum System Method

The minimum system refers to the most basic hardware and software environment that enables the computer to start up or run from the perspective of Service judgment. The minimum system has two forms:

Minimum hardware system: consists of power supply, motherboard, and CPU. In this system, there is no signal line connection, only the power source to the motherboard power connection. In the process of determining whether the core component can work properly, the voice is used to determine whether the core component can work normally;

Minimum Software System: consists of power supply, motherboard, CPU, memory, display card/display, keyboard and hard disk. This minimum system is mainly used to determine whether the system can be started and run normally.

For the minimum software environment, there are the following points to describe the "software:

1. The software environment in the hard disk retains the original software environment, but isolates, such as uninstallation and shielding, as needed during analysis and judgment ). Retain the original software environment, mainly used to analyze and judge the problems of Application Software

2. There is only one basic xx operating system environment in the software environment on the hard disk (it may be to uninstall all applications or reinstall a clean xx operating system ), load the desired application based on the analysis and judgment needs. A clean xx system environment is required to determine system problems, software conflicts, or conflicts between software and hardware.

3. In the minimum software system, you can add or change the appropriate hardware as needed. For example, if the hard disk cannot be started due to a startup failure, check whether the disk can be started from another drive. In this case, you can add a soft drive to the minimum software system or simply replace the hard drive with a soft drive to check. Another example: When judging audio and video faults, the sound card should be added to the minimum software system; when determining network problems, the network card should be added to the minimum software system.

The minimum system method mainly determines whether the system works normally in the most basic software and hardware environment. If it cannot work properly, it can be determined that the most basic software and hardware components are faulty, which can be used for fault isolation.

The combination of the least system method and step-by-step addition method can quickly locate faults that occur in other board software and improve the maintenance efficiency.

3. Step-by-Step addition/removal

The add-on method is based on the minimum system. Only one part, device, or software is added to the system at a time to check whether the fault phenomenon disappears or changes, so as to determine and locate the fault location.

The step-by-step removal method is opposite to the step-by-step addition method xx.

The step-by-step addition/removal method must be used with the replacement method to locate the fault location more accurately.

Iv. Isolation

It is a method to block hardware or software that may prevent fault judgment. It can also be used to isolate conflicting hardware and software to determine whether a fault has changed.

The software and hardware shielding mentioned above is to stop or uninstall the software. For the hardware, it is to disable or uninstall the driver in the Device Manager, or simply remove the hardware from the system.

V. replacement method

Replacement is a maintenance method that uses components to replace faulty parts and determine whether the fault disappears. Good components can be of the same model or different models. The order of replacement is generally:

1. Consider the parts or equipment to be replaced based on the fault phenomenon or the fault category in Part 2;

2. replace them in a simple and complex order. For example, if the memory, CPU, and motherboard are used to determine whether the printing driver is faulty, consider whether the printing cable is faulty, finally, check whether the printer or parallel port is faulty;

3. First, check the connection lines and signal lines connected to faulty parts. Then, replace the faulty parts, and then replace the power supply parts, finally, it is related to other components.

4. Consider the first part to be replaced from the failure rate. Parts with high failure rate can be replaced first.

Vi. Comparison Method

The comparison method is similar to the replacement method, that is, to compare the appearance, configuration, and running phenomena of components with faulty components, you can also compare them between two computers, to determine the environment settings and hardware configurations of the faulty computer, and locate the fault location.

VII. Temperature Reduction Method

In the process of on-site service, due to the restrictions of tools, the use and maintenance of the method is different. In the door-to-door service heating method, you can try to reduce the computer's ventilation capability with the user's consent, and the computer's own fever will warm up; the cooling methods include: 1) generally, select a time period with a low ambient temperature, such as a time period early or later. 2) shut down the computer for 12 ~ More than 24 hours; 3) use an electric fan to blow to a faulty machine to speed up cooling.

8. Method

The hitting method is generally used to reproduce a fault by means of vibration, proper distortion, or even hitting a part or a specific part of the equipment with a rubber hammer, A maintenance method for determining faulty parts.

9. Suggestions on cleaning computer products

Some computer faults are often caused by a large amount of dust in the machine. This requires us to observe whether there is much dust inside and outside the faulty machine during the maintenance process. If yes, dust removal should be performed first, and further judgment and maintenance should be conducted. Pay special attention to the following aspects during the dust removal process:

1. Clean the air duct

2. Clean the fan.

In the cleaning process of the fan, it is best to clear its dust, In the Fan Shaft, point a little table oil, enhance lubrication.

3. Clean the connector, seat, slot, and card Gold finger.

To clean the golden finger, you can use an eraser to wipe the golden finger or alcohol cotton.

Removal of oxidation on the metal pins of the plug, seat, and slot: one is to wipe with alcohol, the other is to use a metal pad (such as a small word to change the cone) on the metal pin gently scratch.

4. Clean the pins of large-scale integrated circuits and components.

When cleaning, use a small brush or a vacuum cleaner to remove dust. At the same time, observe whether the pins have the phenomenon of virtual welding and moisture, and whether the components have the phenomenon of deformation, discoloration or liquid leakage.

5. Pay attention to the cleaning tools used

Cleaning tools are anti-static first. Such as clean with a small brush, should be made of natural materials brush, disable plastic brush. Second, if the metal tool is used for cleaning, the power supply must be cut off and the metal tool should be discharged with static electricity.

Tools used for cleaning include: Small brush, leather tiger, vacuum cleaners, rags, alcohol (plastic casings that cannot be used to wipe chassis, monitors, etc ).

6. If it is wet, try to dry it before using it. Available tools such as electric fans and hair dryers can also make them dry naturally.

10. Several Methods and suggestions for Software Debugging

1. xx system.

The main adjustment content is xx System Startup File, system configuration parameters, component files, viruses, etc.

Fix xx as the System Startup File.

1) For Windows 9x system, use the SYS command to fix the problem (ensure that MSDOS. SYS is larger than 1 kb). However, ensure that the partition parameters are correct before the fix. This can be implemented using software such as DiskMap;

2) For Windows 2000/XP, there are two Methods: To fix the Startup File, use the fixboot command, repair the Master Boot Record, and use the fixmbr command.

Adjust xx as the system configuration file.

A. There are many tools available for the Windows 9x system, such as msconfigcommand to register the table and restore command (scanreg.exe, which requires running in the DOS environment. In addition, if you want to use scanreg.exe to restore the registry, it is best to use the second backup file in the recovery menu listed;

B. for Windows 2000, there are fewer tools available than Windows 9x, but some Debugging commands can be used in windows 98 (for example, Msconfig commands under Windows 98 can be used in Windows 2000 );

C. For Windows XP systems, the tools available are mainly Msconfig commands;

D. Adjust the power management and related services. You can run the following command: Enter gpedit. msc in the "run" text box;

E. All xx systems can be debugged through the control panel, Device Manager, and Computer Manager (not available in Windows 9x.

Fix component files (including. DLL and. VXD)

A. add or delete A program to reinstall the program;

B. Extract and install FROM THE. CAB file;

C. You can use the System File Checker (sfc.exe command) to fix files with errors;

D. Copy and overwrite from a good machine.

Check for viruses in the system.

We recommend that you use the virus scanning and removal software in the command line mode and directly access NTFS partitions.

2. install and configure the driver.

It mainly adjusts whether the device driver matches the device, whether the version is appropriate, and whether the corresponding device can respond normally under the action of the driver.

A. it is recommended that xx be used as the system's automatic identification first (except for those with special requirements, such as display card drivers, sound card drivers, and drivers of non-plug-and-play devices ), then, force installation is considered. This is conducive to determining whether the device is good or bad;

B. If xx is used as the built-in driver of the system, use the built-in driver of the device if it is still abnormal or cannot meet application requirements;

C. To replace the device, uninstall the driver before replacing it. Uninstall the driver, which can be detached from the Device Manager, unmounted from safe mode, deleted from the INF directory, and finally uninstalled through the registry;

D. when updating the driver, if there is a problem with the direct upgrade, you must uninstall the driver before updating it.

3. Disk status.

Check whether the partitions on the disk can be accessed, whether the media is damaged, and whether the files stored on the disks are complete.

Available adjustment tools:

A. DiskMap facilitates the retrieval of correct partitions;

B. Fdisk and Fdisk/MCM check whether the partition is correct and restore the Master Boot Record to the original state;

C. If you want to repartition or view a partition when the disk capacity is larger than 64 GB, use the Fdisk command in the disk partition floppy disk that is attached to the disk. This command can be replaced by the Fdisk command in windows Me;

D. format, Scandisk, and the disk detection program provided by the vendor to check whether the disk media has bad channels;

E. If the file is incomplete, You need to rename the file before using the method described in "xx system.

4. Application Software.

Such as whether the application software is compatible with xx system or other applications, whether the use and configuration are consistent with those described in the instruction manual, and whether the relevant procedures and data of the application software are complete;

5. BIOS settings.

1) restore to the optimal state if necessary. Suggestion: recover the BIOS to the optimal state (usually the State at the factory) during maintenance, and then gradually set the appropriate value according to the application's needs.

2) You do not have to refresh the BIOS to the latest version. Sometimes you should consider downgrading the version.

6. Rebuild the system.

When the hardware configuration is correct and the user's permission is obtained, you can reconstruct the system to identify software faults such as xx system. If the user does not agree, we recommend that you use your own hard disk, to reconstruct the system. In this case, it is best to re-build the system and gradually restore the state of the user's original hard disk to determine the fault point.

1) the system must be restored with one click, followed by the restored installation, and finally completely re-installed. How to restore installation:

For Windows 9x systems, you can directly install them from the CD, or execute tools \ sysrec \ pcrestor. bat to resume installation. During the recovery installation, the installation process may be affected due to the existence of win.com. In this case, you can delete win.com in the Windows directory and reinstall it.

Another method of restoring installation is to change the name of System.1st in the root directory to System. dat, overwrite the file with the same name in the Windows directory, and then restart. However, this method is not a true re-installation, but similar to a completely re-installation.

For Windows XP or Windows systems, use the installation CD to start them. On the installation page, select repair and installation. When selecting R, two options will appear: one is Quick repair, use this option for simple problems. The other is the fault recovery platform. You only need to select the correct installation directory to enable the fault recovery platform. The fault recovery platform interface is similar to the DOS interface.

2) to ensure the system is clean, run the Fdisk/MBR command (Clear.com is also available) before installation ). If necessary, then run the format <drive letter>/u [/s] command.

3) Be sure to use a random version or a genuine version of xx as the system installation media for installation.