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Handling Skills for Common Problems of Computer Hardware
Understanding BIOS
I. BIOS Functions
Functionally, BIOS is divided into three parts:

1. Self-inspection and initialization procedures;
2. Hardware interrupt handling;
3. Program service request.

Let's have a detailed understanding of the functions of its various parts:

(a) self-inspection and initialization
This part is responsible for starting the computer. It has three parts. The first part is used to detect the hardware part when the computer is just powered on. It is also called power-on self-test (POST). Its function is to check whether the computer is in good condition, such as whether there is any fault in the memory, etc. The second part is initialization, which includes creating interrupt vectors, setting registers, initializing and detecting some external devices, etc. The most important part is BIOS setting, which mainly refers to some parameters of hardware setting. When the computer starts up, these parameters will be read and compared with the actual hardware setting. If they do not conform, the startup of the system will be affected.
The last part is the boot program, whose function is to boot DOS or other operating systems. BIOS first reads the boot record from the starting sector of the floppy disk or hard disk. If it is not found, it will show that there is no boot device on the display. If it is found, it will transfer the control of the computer to the boot record. The boot record will load the operating system into the computer. After the computer starts successfully, this part of BIOS tasks will be completed.

(2) program service processing and hardware interrupt processing
These two parts are two independent contents, but they are closely related in use.
Program service handlers mainly serve application programs and operating systems. These services are mainly related to input and output devices, such as reading disks and outputting files to printers. In order to complete these operations, BIOS must deal directly with the I/O devices of the computer. It issues commands through the ports, transmits data to various external devices and receives data from them, so that the program can be separated from specific hardware operations, while hardware interrupt processing processes the hardware requirements of the PC respectively. Therefore, these two parts serve software and hardware respectively, and are combined together to make the computer system run normally.

The service function of BIOS is realized by calling interrupt service program. These services are divided into many groups, each group has a special interrupt. For example, video service, the interrupt number is 10H;; Screen printing, interrupt number is 05H;; Disk and serial port service, interrupt 14H, etc. Each group is subdivided into different service numbers according to specific functions. What peripherals and operations the application program needs to use only need to be explained with corresponding instructions in the program, without direct control.

II. Types of BIOS

Because BIOS directly deals with system hardware resources, it is always aimed at a certain type of hardware system, and each hardware system is different, so there are different kinds of BIOS. With the development of hardware technology, different versions of the same BIOS have appeared successively. The new version of BIOS is more powerful than the old version.

At present, BIOS is divided into three types: AWARD, AMI and PHOENIX. The manufacturer's mark can be seen on the chip. Among them, PHOENIX and AWARD have merged (AWARD has acquired PHOENIX). AWARD BIOS is generally used on motherboards, although it is labeled PHOENIX-AWARD. The BIOS of a brand name machine is generally PHOENIX's BIOS. However, for INTEL's original motherboard, its BIOS is specially customized by PHOENIX. The general notebook is the original phoenix style, while the desktop is the award style (to brush BIOS, it is better to confirm your motherboard brand and model first)

Let's move on to the topic you want to know most.

  Award BIOS:
1 Short: The system starts normally.
2 short: general error (enter CMOS Setup and reset incorrect options)
1 long and 1 short: RAM or motherboard goes wrong (try to replace it with another memory; if it still fails, the motherboard will have to be replaced)
1 long and 2 short: display or display card error.
1 long and 3 short: keyboard controller error (check motherboard)
1 Long 9 Short: Main Board Flash RAM or EPROM Error, BIOS Damage (Try Replacing Flash RAM)
Constantly ringing (long sound): the memory module is not tightly inserted or damaged (if the memory module is not valid after re-insertion, only the memory module can be replaced)
Keep ringing: the power supply and monitor are not connected to the video card (check all plugs)
Repeated short ring: there is a problem with the power supply.
No sound, no display: there is a problem with the power supply.
  Phoenix BIOS :
1 Short: The system starts normally.
1 short, 1 short, 1 short: initialization of system power-on self-test failed.
1 short 1 short 2 short: motherboard error.
1 Short 1 Short 3 Short: CMOS or Battery Error.
1 short 1 short 4 short: ROM BIOS verification failed.
1 short 2 short 1 short: system clock error.
1 short 2 short 2 short: DMA initialization failed.
1 Short 2 Short 3 Short: DMA Page Register Error.
1 short 3 short 1 short: RAM refresh error.
1 Short 3 Short 2 Short: Basic Memory Error.
1 Short 3 Short 3 Short: Basic Memory Error.
1 short 4 short 1 short: basic memory address line error.
1 short 4 short 2 short: basic memory check error.
1 short 4 short 3 short: EISA sequencer error.
1 short 4 short 4 short: EASA NMI port error.
2 short, 1 short, 2 short to 2 short, 4 short, 4 short (i.e. a combination of all sounds starting with 2 short): basic memory error.
3 Short 1 Short 1 Short: Error from DMA Register.
3 Short 1 Short 2 Short: Main DMA Register Error.
3 short 1 short 3 short: main interrupt processing register error.
3 Short 1 Short 4 Short: Error from Interrupt Processing Register.
3 short 2 short 4 short: keyboard controller error.
3 Short 3 Short 4 Short: Memory Error of Display Card.
3 short 4 short 2 short: display error.
3 Short, 4 Short, 3 Short: No Display Read Only Memory Found.
4 Short 2 Short 1 Short: Clock Error.
4 Short 2 Short 2 Short: Shutdown Error.
4 short 2 short 3 short: A20 gate error.
4 Short 2 Short 4 Short: Protection Mode Interrupt Error.
4 Short 3 Short 1 Short: Memory Error.
4 short 3 short 3 short: clock 2 wrong.
4 Short 3 Short 4 Short: Real Time Clock Error.
4 short 4 short 1 short: serial port error.
4 Short 4 Short 2 Short: Parallel Port Error.
4 short 4 short 3 short: digital coprocessor error.
1 Short: Memory refresh failed. (Replace Memory Module)
2 short: memory ECC check error is commonly referred to as memory parity error (can enter CMOS setting,
Turn off the memory parity parity check option and set it to Disabled. But generally speaking,
Memory chips have parity check and parity check is turned on in CMOS setting, which is stable for microcomputer system
Qualitative analysis is beneficial. )
3 short: system basic memory (64KB first) check failed (replace memory)
4 short: system clock error. (Repair or Replace Motherboard)
5 short: CpU error, but it is not necessarily all the fault of CpU itself, it may also be CPU socket or somewhere else
Problem, if this CpU is normal on other motherboards, the error is definitely the motherboard.
6 short: keyboard controller error (if the keyboard is not plugged in, then easy to do, just plug in; If the keyboard is connected
If you receive a normal but error message, you may as well try a good keyboard. Otherwise, it is keyboard control.
There is a problem with the chip or related parts)
7 short: system real mode error, cannot switch to protection mode (also belongs to motherboard fault)
8 Short: Display Memory Read/Write Error The memory chip on the video card may be damaged (if the memory chip is pluggable
, as long as find out the bad piece and replace it, otherwise the video card needs repair or replacement).
9 Short: ROM bIOS Check Error (Try to change a good bIOS of the same type. If it proves that there is something wrong with the BIOS,
You can try to restore it by rewriting or even hot-plugging)
10 Short Register Read/Write Error (Only Repair or Replace Motherboard)
11 Short Cache Error.
1 Long 3 Short: Memory Error.
1 long and 8 short: display test error.
Compatible BIOS:
1 Short: The system is normal.
2 Short: The system power-on self-test (POST) failed.
1 long: power supply error, if there is no display, it is a display card error.
1 long 1 short: motherboard error.
1 long 2 short: graphics card error.
1 short 1 short 1 short: power supply error.
3 long and 1 short: keyboard error.
1.[ fault description:] in xp, only disk c can be seen, but in fact, no partition can be found
[Solution:] Analysis is the partition table failure. Start the computer with the startup disk. Note that one software in the startup disk is diskman. Therefore, in Dos real mode, use diskman to create partitions. diskman is very simple to use. The Chinese menu and the command to rebuild partitions are in the tools menu. Rebuild the partition and restart it.2. [Fault Description:] COMS CHECKSUM :ERROR DAULTLOAD appears every time the machine starts POST[Solution:] I took the motherboard battery off before and suspected that the battery was not good.3.[ Fault Description:] After startup, the XP scroll bar jumps out of the advanced startup menu and prompts for a hardware or software fault (ha ha equals no mention). No matter which method is chosen, the system cannot be successfully started.[Solution:] Start from the CD-ROM drive, put in a system maintenance CD, and try to load a winPE mini CD system. An error will be prompted during the loading process (the system is being loaded into memory at this time). Initially identified as a memory module problem, open the chassis, carefully check the memory module and the memory slot, and find no difference except a little dust. Use a brush to clean up the dust in the slot, use an eraser to remove the golden finger, insert it again, and the system can be accessed normally after starting up. Troubleshooting.[Cause of Failure:] It is estimated that the poor contact between the gold finger and the slot was caused by the accidental collision of the chassis or dust.4.[ fault description:] double-click the taskbar time cannot modify the system time, prompting "you do not have permission to modify the system time, please contact the administrator"[resolution:] start-> run-> gpedit. MSC-> computer configuration ------>windows settings-> security settings-> local policy-> user security assignment-> change system time5. [Fault Description:] The small horn under the taskbar is missing.[Solution:] When entering the control panel and checking the option to place the volume icon on the taskbar, you will be prompted that sndvol32.exe cannot be found. I think the sound driver is broken, so I can't reinstall the sound driver. Re-installing the motherboard driver and sound driver is still not possible. Finally, I remembered that there should be this file in the I386 directory of the installation disk, so I went in and found a file named sndvol32.ex _ which was copied to the directory c: \ windows \ system32 and renamed as sndvol32.exe. After entering the control panel and checking the option of placing the volume icon in the taskbar, the cute little horn will appear in the taskbar.6. [fault description:] internal application error occurred while running media player windows media playerThe 0x00000008 memory referenced by the 0x4345399c instruction appears again `the memory cannot be read''[Resolution:] Start-Run, EnterRegsvr32 jscript.dll ReturnRegsvr32 vbscript.dll Return7.[ fault description:]: when the computer is turned on, the screen "fixed" on the first screen has not responded for a long time.Unable to access the system[Resolution:] Remove the chassis and locate the battery on the motherboard. Take it off and put it back in.Restart again and you can enter the system.8.[ Fault Description:] Memory Damage Causes System to Frequently Report Registry ErrorsThis kind of fault is quite common, which shows that the system can be started normally. However, when entering the desktop, the system will prompt the registry to read the error, and the computer needs to be restarted to repair the error. However, after the computer is started again, it is still the same fault.[Solution:] We can enter the safe mode, type the "MSCONFIG" command during the operation, remove the "V" before ScanRegistry in the "Start" item, and then restart the computer. If the fault is removed, it indicates that the problem is really caused by a registry error. If the fault still exists, it can basically be concluded that there is a problem with the machine's memory. In this case, it is necessary to replace it with a memory module with good performance to check whether there is the same fault.9.[ fault description:] in the task manager, the cpu process shows 100%, and no program is running at this time. (at this time, system id process takes up 1% of the cpu, and system takes up 99% of the CPU). it cannot shut down normally, and finally the shutdown screen crashes.[Solution:] I thought I was poisoned, but later found out that the CDMA wireless Internet modem and the system were not compatible, resulting in high cpu usage and failure to shut down. In case of such problems, it is necessary to check whether the computer is connected with new hardware or installed with any software. The high cpu usage of the system id process is normal because it is an empty process.10.[ Malfunction]: The computer cannot
Finally, the main board battery discharge method is adopted. The startup is normal.
Conclusion: The main board test fails due to the confusion of CMOS parameter setting. The above' discharging method' can only be used if CMOS cannot be entered.
11. [Fault Description]: Downloaded antivirus software cannot be installed.
After downloading, you can't install it. You think that what you downloaded is fake. There is nothing fake these days. I'm afraid! I went to many large professional websites to download n times and installed n times, so I can no longer doubt that it is a download problem, but I still can't install it. The installation was only a flash and nothing could be filled in. )
[Solution]: First of all, it is suspected that the original "soft killing" did not have a clean government, but it was not found to be the problem. Then I went to safe mode and installed it at once. I don't know if it is a good way to solve the problem immediately and upgrade normally, but it can really solve the problem.
12.[ Fault Description:] After the xp scroll bar appears at startup, when the welcome screen appears quickly, the black screen cannot see anything and can only be restarted. If it does not work for the second time, the welcome screen may not appear, but it will appear again when the desktop is about to appear, and it can only be restarted after many restarts.
However, the same situation will occur when computers are opened in the second day.
[Solution:] I began to suspect that it was a system problem these days, but after I reinstalled the system, this situation also occurred. Then I suspected that it was a video card. I removed the video card and carefully observed it. I found that several capacitors exploded, which further deepened my suspicion. I went to my friend to borrow a video card and tried it. everything returned to normal.