Hardware Fault Judgment Guide

Most computer faults are software faults, so there is no need to migrate the entire machine before it is determined to be a hardware fault. Even if the hardware is faulty, there is no need to move the entire machine. You only need to take the faulty parts. Therefore, it is necessary for us to understand the diagnostic and testing methods for hardware faults. In the future, when a computer fails, we do not need to move the entire machine away (of course, it is best not to fail out !).

Faults and Countermeasures

If you want to make a comprehensive analysis of computer faults, I am afraid you need to write a book, which is not easy. Software faults have been described in various newspapers and periodicals. Therefore, we will only introduce the symptoms, causes, and solutions of hardware faults.

I. Computer Startup Process

I. First, let's take a look at the computer startup process.

1. bootstrap loader stored in ROM (read-only memory)ProgramAnd the self-diagnosis program is moved to Ram (Random storage.

2. As bootstrap loader runs, the operating system stored in the auxiliary memory device sends system files to ram.

3. Execute the system file IO. sys and msdos. sys. "Starting windowsn98 ...... .

4. If config. sys exists, run it.

5. Execute the command.com file of the system file.

6. If autoexec. Bat exists, execute it.

7. Read the Windows Initialization Files "system. ini" and "win. ini", and then read the Registry file.

8. After the startup is completed, an initial screen is displayed and the operating system is running. In this process, the rom bios of the motherboard monitors whether the hardware is abnormal, including hardware faults, wiring, and installation of various cards. If an error occurs, the screen will show nothing and start and stop. In this case, hardware faults may occur.

Ii. system startup sequence

1. The on-display, keyboard, and chassis lights on the PC power supply flash.

2. Detect the video card-a short video card information appears on the screen.

3. Detect memory-the memory capacity information appears on the sound screen of the beep.

4. Run bios. A brief BIOS information is displayed on the screen.

5. Check other devices-information about other devices (CPU, HDD, Mem ...).

6. Execute the OS (operating system) initialization file-Starting Windows 98.

Iii. Make a sound on the motherboard during startup. You can use this sound to determine the error.

The voice representation varies depending on the form of the motherboard.

Ami BIOS: 1 short: Memory refresh failed 2 short: Memory verification error 3 short: basic memory error 4 short: system clock error 5 short: CPU Error 6 short: keyboard error 7 short: real-time mode error 8 short: Memory Display Error 9 short: rom bios verification error 1 long 3 short: Memory Error

Ward BIOS: 1 short: boot normal 2 short: non-fatal error 1 long 1 short: Display Error 1 long 2 short: keyboard error other BIOS can refer to relevant information, here is not detailed introduction.

2. obfuscated software faults must be clearly divided into hardware faults and software faults in the region. Otherwise, it will take a lot of effort to move the computer to the computer market, the shopkeeper tells you what it is like when a software fault occurs. In particular, startup faults may also be caused by software faults. Next, let's take a look at the startup exceptions caused by software faults.

I. CMOS setup errors if the hard disk settings in CMOS setup are incorrect, the hard disk cannot be started with the operating system (Windows) in the hard disk because the computer cannot identify the hard disk. Check the content of CMOS setup when the image appears but cannot be started. To correctly identify the hard disk, you can use the "Ide HDD Auto Detection" option in CMOS setup.

Ii. System File errors: command.com, Io. sys, msdos. sys, and drvspace. Bin files are required for Windows startup. If these files are damaged, they cannot be started even if the hard disk is identified. You can use the "sys.com" file to restore these files. After starting with the boot disk, type "sys C.

Iii. File initialization error: "autoexec. bat "," config. sys "," system. ini "," win. ini "," user. dat "," system. dat "Six files. However, if an error occurs during reading, the startup will fail. These files are difficult to recover, so you need to use methods such as Windows resetting. However, this is not a hardware fault. You do not need to take your computer to the computer market.

Iv. Windows errors most of the faults on the Windows initial screen are software faults. Conflicts between programs or driver issues. This problem can be solved by reading books and other methods.

Iii. hardware faults that are not faults. Although they are not faults, they often result in incorrect user assembly or loose plug-in. In this case, you can turn on your computer to check for wiring, plug-in, and other errors. When purchasing new hardware, CD-ROM, and other Eide devices, be sure to set the device that is connected in the middle to "slavee", set the device that is connected to the edge to "master ", an error may occur when the device cannot be started or used if the device is set incorrectly.

Test Method

Next, let's take a look at the basic test methods for hardware faults. When the monitor does not have any image, you can use the following method to test the faulty part.

1. Prepare a workbench first.

2. Remove the motherboard from the chassis, unplug all the components on the motherboard, leaving only the CPU and ram, and then place the motherboard on the workbench.

3. Connect the regulated power supply to the motherboard.

4. Insert the video card into the AGP slot. Of course, if it is a PCI graphics card, it is inserted into the PCI slot. When inserting a video card, make sure that the gold-plated part of the video card is completely inserted into the slot.

5. Connect the video card to the monitor after connecting the power plug-in of the monitor.

6. Turn on the power of the monitor, and then turn on the power switch of the chassis. Then use a metal rod to access the power switch of the motherboard. The power switch of the motherboard is the part connected to the power switch of the chassis, which is generally marked as "pwr sw" or "Power se ".

7. If the BIOS version information is displayed on the screen and the screen is normal, the CPU, motherboard, Ram, video card, and power supply are normal. usually, the component that is prone to failures is the "video card", "motherboard", and "Hard Disk" order.

8. Connect the hard disk and the soft area for detection. Connect the CD-ROM detection, then the sound card. Modem and other connections. If no picture is displayed, it indicates that the connected component is faulty or has compatibility problems. Only the faulty part must be processed.

9. Chassis problems sometimes occur when the motherboard is installed into the chassis, resulting in startup failure. Therefore, if there is no problem in the above part check, you can install the motherboard on the chassis for testing. If there are no errors in the test, it indicates that it is a CMOS setup error, a driver, and other software problems.