Basic principles and methods of computer maintenance _ hardware Maintenance

First, the maintenance judgment must start from the simplest thing
Simple things, on the one hand, refers to observation, on the other hand refers to the simple environment.
The simple thing is observation, which includes:
1, the environment surrounding the computer-location, power supply, connection, other equipment, temperature and humidity, etc.
2, the phenomenon displayed by computer, the content of display, and their similarities and differences with normal situation;
3, the internal environment of the computer-dust, connection, the color of the device, the shape of the components, led status, etc.
4, the computer hardware and software configuration-what kind of hardware installed, the use of resources, the use of the operating system, which installed the application software, hardware settings driver version, and so on.
The simple environment includes:
1. The smallest system to be mentioned in the future;
2, in the judgment of the environment, including only basic operating parts/software, and suspected faulty parts/software;
3, in a clean system, add the user's application (hardware, software) to analyze and judge
Starting from simple things, is conducive to focus on energy, and is conducive to fault diagnosis and positioning. It must be noted that after careful observation, it is necessary to judge and repair.
Second, according to the observed phenomenon, to "first think and then do"
First think and then do, including the following aspects:
First of all, think about how to do, where to start, and then the actual hands. It can be said that the first analysis of the judgement, and then maintenance.
Secondly, for the observed phenomenon, as far as possible to consult the relevant information, see if there is no corresponding technical requirements, the use of characteristics, and then according to the information, combined with the following to discuss the content, and then proceed with maintenance. String 9
Finally, in the process of analysis and judgment, according to their own knowledge, experience to make judgments, for their own do not know or do not understand, we must first to have experienced colleagues or your technical support engineers to consult and seek help.
Third, in the majority of computer maintenance judgments, must be "first soft and hard:
That is, judging from the whole process of maintenance, always first judge whether the software failure, first check the software problem, when the software environment is normal, if the fault can not disappear, and then proceed to check from the hardware.
Four, in the maintenance process should distinguish between primary and secondary, namely "catch principal contradiction"
When you reproduce the symptom, you may sometimes see that there is more than one symptom of a failed machine, but there are two or more than two fault phenomena (such as: the start-up process is not obvious, but the machine is also started, at the same time after the startup, there is a crash phenomenon, etc.), the last, should first judge, repair the main fault phenomenon, when repaired, Re-repair minor fault phenomenon, sometimes the secondary fault phenomenon is no longer required maintenance.
§1.2 Basic method of computer maintenance string 7

I. Observation of the Law
Observation is the first method in the process of maintenance judgment, which runs through the whole maintenance process. Observation should be not only serious, but also comprehensive. The things to observe include:
1, the surrounding environment;
2, hardware environment. including connectors, seats and slots, etc.;
3, Software environment;
4, the user operates the custom, the process string 2


Second, minimum system method
Minimum system is the most basic hardware and software environment that can make a computer boot or run from the angle of maintenance judgment. There are two forms of the smallest system:
Hardware minimum system: consists of power supply, motherboard and CPU. In this system, there is no signal cable connection, only the power supply to the motherboard power connection. In the process of judging, it is through the sound to judge whether the core component can work properly.
Software minimum system: consists of power supply, motherboard, CPU, memory, display card/monitor, keyboard and hard disk. This minimum system is mainly used to determine whether the system can perform normal start-up and operation.

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For the software minimum environment, the "software" has the following points to explain:
1, the software environment in the hard disk, keep the original software environment, only in the analysis and judgment, according to the need for isolation, such as unloading, shielding and so on. Retain the original software environment, mainly used to analyze and judge the application software problems
2, the software environment in the hard disk, only a basic operating system environment (may be unloaded all applications, or reinstall a clean operating system), and then according to the needs of analysis and judgment, loading the required application. Need to use a clean operating system environment, is to determine the system problem, software conflicts or hardware and the conflict between the problems.
3, under the software minimum system, you can add or change the appropriate hardware as needed. For example, when judging a startup failure, because the hard drive does not start, you want to check if you can boot from another drive. At this point, you can add a floppy drive under the software minimum system or simply replace the hard drive with a floppy drive to check. Another example: In the judgment of audio and video faults, should need to add a sound card in the software minimum system, when judging network problems, should be in the software minimum system to add a network card.
The minimum system method is mainly to determine whether the system can work properly in the most basic software and hardware environment. If can not work correctly, can determine the most basic hardware and software components have trouble, thus play the role of fault isolation.
The minimum system method combined with the incremental method can quickly locate the failure of other board software and improve the maintenance efficiency. String 4


Third, step-by-Step Add/Remove method
Gradually add the method, based on the smallest system, each time only add a part/device or software to the system, to check whether the phenomenon disappeared or changed, in order to determine and locate the fault site.
The step-by-step removal is just the opposite of the step-by-step approach to adding the method.
The gradual addition/removal method should be combined with the replacement method to accurately locate the fault site. String 2


Iv. Segregation Law
is a method of judging the hardware or software that may obstruct the fault judgment. It can also be used to distinguish conflicting hardware and software from each other to determine whether a fault has changed.
The hardware and software shielding mentioned above, for the software, that is, to stop its operation, or uninstall, for hardware, in Device Manager, disable, uninstall its driver, or simply remove the hardware from the system.

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V. Replacement method
The replacement method is to use good parts to replace the parts that may be faulty, in order to determine whether the failure phenomenon is a maintenance method. The good parts can be of the same type, or they may be of different models. The order of substitution is generally:
1, according to the phenomenon of failure or the second part of the fault category, to consider the need for replacement parts or equipment;
2, in the first simple after the complex order to replace. such as: first memory, CPU, after the motherboard, and if you want to judge the printing failure, you can first consider whether the printing driver has a problem, and then consider whether the printing cable is faulty, and finally consider whether the printer or the mouth is faulty, etc.
3, the first Test and suspected faulty parts connected to the connection line, signal line, etc., after the replacement of the suspected faulty parts, and then replace the power supply components, and finally related to other parts.
4, from the failure rate of components to consider the first replacement parts. Parts with high failure rates are replaced first. String 5


Vi. Comparative Law
The comparison method and the substitution method are similar, namely uses the good component and the suspected faulty component carries on the appearance, the disposition, the operation phenomenon and so on aspect comparison, also may compare in the two computers, in order to judge the fault computer in the environment setting, the hardware disposition difference, thus discovers the fault part. String 7


Seven, lifting temperature method
In the door-to-door service process, the rise and drop method due to the limitations of the tool, its use and maintenance is different. The heating method in the door-to-door service, users can agree to the situation, to try to reduce the computer's ventilation capacity, sad computer's own fever to heat up; cooling methods are: 1 generally choose a lower ambient temperature period, such as morning or later time, 2 to make computer downtime more than 12-24 hours and other methods to achieve 3) The fan is blown to the fault machine to speed up the cooling rate. String 3


Eight, the Beat method
Beat method is generally used in the suspected computer in a bad contact with the fault, through vibration, appropriate distortion, or even with a rubber hammer knock parts or equipment to the specific parts of the failure to reproduce, so as to judge the fault parts of a maintenance method.

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IX. recommendations for cleaning computer products
Some computer malfunctions, often due to more dust in the machine, which requires us in the maintenance process, pay attention to the failure of the machine, the external whether there are more dust, if it is, should be first to dust, and then follow-up judgement maintenance. In the dust removal operation, the following aspects should pay special attention to:
1, pay attention to the clean air duct
2, pay attention to the cleaning fan
In the process of cleaning the fan, it is best to remove the dust, to be able to point a little clock oil in the fan shaft, and to enhance lubrication.
3, pay attention to plug, seat, groove, plate card gold finger part of the cleaning
The gold finger clean, may use the rubber to wipe the gold finger part, or may use the alcohol cotton to wipe.
Plug, seat, groove metal pins on the removal of the oxidation phenomenon: one is to wipe with alcohol, one with metal pieces (such as a small screwdriver) in the metal pin gently scraping.
4, attention to large-scale integrated circuits, components and other pins in the cleaning
Clean, apply the brush or vacuum cleaner to remove dust, at the same time to observe the PIN has no virtual welding and damp phenomenon, the components are deformation, discoloration or leakage phenomenon.
5, pay attention to the use of cleaning tools
Cleaning tools, the first is anti-static. such as cleaning with the brush, should use natural materials made of brush, disable plastic brush. Second, if the use of metal tools to clean, must cut off the power, and metal tools to discharge static electricity treatment.
Tools for cleaning include: brush, fur tiger, vacuum cleaner, rag, alcohol (not used to wipe the chassis, display, etc. plastic shell).

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6, for the more humid situation, should find ways to make it dry and then use. Available tools such as electric fans, hair dryers, etc., can also let its natural air-dry.
Ten, several methods and suggestions of software debugging
1, operating system aspects.
The main adjustment content is the operating system startup files, System configuration parameters, component files, viruses and so on.
Repair the operating system startup files.
1 for Windows 9x systems, the SYS command is available to fix (to ensure that the Msdos.sys size is above 1KB), but requires that the partitioning parameter be correct before fixing. This can be achieved using software such as Diskmap;
2 for Windows 2000/XP Systems, there are two ways to fix startup files, use the fixboot command, repair the master boot record, and use the FIXMBR command.
Adjust the operating system configuration file.
A. For Windows 9x systems, there are a number of tools available, such as the Msconfig command, the System File Checker, the registry backup and Restore command (Scanreg.exe), which requires running in a DOS environment. In addition, if you want to use Scanreg.exe to restore the registry, it is best to use the list of the recovery menu of the second backup file, etc.;
B. For Windows 2000 systems, there are fewer tools available than Windows 9x, but some debugging commands can be used under Windows 2000, such as the Msconfig command under Win98, in Win98;
C. For Windows XP systems, the tools available are mainly MSCONFIG commands;
D. Adjust power management and related services, the command you can use is to enter gpedit.msc in the "Run" text box; string 2
E. All operating system debugging, through the control Panel, Device Manager, Computer Manager (Windows 9x system is not) to debug the system.
component files, including. Dll. VXD, etc.) repair
A. Reinstall by adding A removal program;
B. Adoption from. CAB file to extract the installation;
C. Use the System File Checker (Sfc.exe command) to fix files with errors;
D. Copy cover from a good machine.
Check the virus in the system.
It is recommended that you use a command-line approach to virus killing software and direct access to such things as NTFS partitions.
2, equipment driver installation and configuration.
The main adjustment device driver is compatible with the device, the version is appropriate, the corresponding device under the action of the driver can be normal response.
A. It is best to be automatically identified by the operating system (unless specifically required, such as some special requirements for the display card driver, sound card driver, non-Plug and Play device driver, etc.), and then consider forced installation. This is conducive to judging the quality of equipment;
B. If there is an operating system with its own drive, the first use, still can not be normal or can not meet the application needs, the use of equipment with the drive;
C. Replace the equipment, you should first uninstall the drive and then replace. Uninstall the drive, uninstall from Device Manager, uninstall from Safe mode, and delete in the INF directory, and finally uninstall through the registry;
D. When updating drivers, if there is a problem with the direct upgrade, you must uninstall and update them first.
3, the disk condition aspect.
Check that the partitions on the disk are accessible, that the media is corrupted, that the files saved on it are intact, and so on. String 4
Available Adjustment tools:
A. Diskmap, easy to retrieve the correct partition;
B. Fdisk and FDISK/MDR, check that the partition is correct and restore the master boot record to its original state;
C. When your hard disk is larger than 64GB, if you want to repartition or view the partition, use the FDISK command on the disk partition diskette that comes with you. This command can be replaced with the Fdisk command under Windows Me;
D. Format, Scandisk, vendor-provided disk testing procedures to check whether the disk media has a bad way;
E. When the document is incomplete, it is required to rename the incomplete document first and then rebuild it using the method described in "Operating system".
4, the application of software.
If the application software is compatible with the operating system or other applications, whether the use and configuration is consistent with the description manual, the application software related procedures, data, etc. is complete, etc.
5, the BIOS setup aspect.
1 if necessary, first revert to the optimal state. Recommendation: In the maintenance of the first to restore the BIOS to the optimal state (usually the state of the factory), and then according to the needs of the application, and gradually set to the appropriate value.
2 The BIOS refresh does not have to be refreshed to the latest edition, and should sometimes be considered for lower versions.
6, the reconstruction system.
When the hardware is properly configured and licensed by the user, the system can be used to determine software failures such as operating systems and, in the case of users ' disagreement, to use their own hard drives to reconstruct the system. In this case, it is best to rebuild the system and gradually restore the state of the user's original hard drive to determine the point of failure.
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1 reconstruction of the system, must be a key to restore the main, followed by the restoration of installation, and finally a complete reinstallation. How to restore the installation:
For Windows 9x systems, install directly from the CD, or perform Tools\sysrec\pcrestor.bat, to restore the installation. During a recovery installation, the installation process may be affected by the presence of Win.com, at which point the win.com can be removed and reinstalled in the Windows directory.
Another type of restore installation is to rename the system.1st under the root directory to System.dat, overwriting the same file under Windows directory, and then reboot. This approach, however, is not a true reinstallation, but is similar to a full reinstall.
For Windows XP or Windows2000 systems, start directly with its installation CD, select Repair installation in the installation interface, and choose R with two options: First, quick fixes, with this option for simple problems, and the other a failover console, which enables the failover console by selecting the correct installation directory. The Fault repair console interface is similar to a DOS interface.
2 to ensure that the system is clean, before the installation, the implementation of the FDISK/MBR command (also available clear.com). If necessary, perform the format < drive letter >/u [/s] command after this.
3 Be sure to use the random version or genuine operating system installation media installation.