Computer troubleshooting experience

Recently, there have been many things, and the mobile phone joystick is broken. Because it is something aging and cannot be repaired, I want to change my mobile phone. I 've been hesitating between the iPhone and gphone. The iPhone's industrial design is good. Just as my friend asked me to help Jailbreak the iPhone, I took the IOS to play, the degree of freedom is too low, the antenna door comes, plus the need to use the disgusting iTunes software. Ah ~~~ Apple is crazy to make money. I am optimistic about gphone and want to start with Droid X. Haha ~~~ The reason for writing this article is as follows. My dad's computer was kicked off by his power supply, and the memory card slot was oxidized and the hard drive was bad. After checking on me for a long time, I felt that I could not check all the problems each time. I needed the right remedy. In retrospect, I had no more than five computers I had repaired. Although I was not very professional, I encountered almost all the problems. I like to split things when I was a child. Basically, some electrical appliances will be disowned by me before they are removed, and many electrical appliances have been repaired. Generally, I solve mechanical problems. Electronic problems, due to the lack of equipment repair, encountered this problem, I can only use the way to change parts to repair. In order to make the process of computer repair more streamlined, I found some information and combined with my own maintenance experience, summarized as follows:

 

Fault description 1: turn on the power, press the power button, the computer does not have any dynamic and static.
　　
Analysis: At this time, the power supply should supply power to the main board and various hardware. If there is no dynamic and static information, the power supply department has separated the problem. (Including motherboard power supply)

Check ideas and methods:
　　
1. If there is a mains supply problem, check whether the power outlet is normal and the power cord is normal.

2. If the power supply of the chassis is faulty, check whether there is a 5 V standby voltage and whether the connection between the motherboard and the power supply is loose. If the voltage is not measured, find a power supply to change it.

3. If there are no problems with the motherboard, the failure of the motherboard will be more likely. First, check whether the connection between the motherboard and the boot button is loose and whether the switch is normal. You can use a wire to disconnect the switch. If not, try replacing a motherboard. (Note: Try to find boards of the same model or same chipset, because other boards may not support your CPU and memory, when an exception occurs, it automatically locks itself. The best way is to discharge CMOS and reset the BIOS.

 

Fault Phenomenon 2: press the power-on button, the fan turns, but the display does not have a picture, the computer cannot enter the normal working status.
　　
Analysis: Fan rotation indicates that the power supply has started, the monitor has no image, and the computer cannot enter the normal working status. This indicates that the computer has not passed the system self-check, and the BIOS settings of the motherboard have not been output to the monitor, faults should occur on the motherboard, video card, and memory. However, sometimes poor power supply and display damage may also cause this fault.
　　
Check ideas and methods:
　　
1. If an alarm is reported, the error is detected. The alarm sound is set by the BIOS on the motherboard. There are two BIOS types: AMI and AWARD. Most motherboards use award bios.
　　
The BIOS of AWARD is set:
Long Sound: the memory stick is not tightly inserted.
Short: the system starts normally.
Two short: the CMOS settings are incorrect and need to be reset.
Long and Short: memory or motherboard error.
One long and two short: Incorrect display or video card.
One long, three short: Incorrect keyboard controller.
One long, nine short: The Flash RAM or EPROM of the motherboard BIOS is incorrect.
　　
The BIOS of the AMI is set:
Short: Memory refresh failure.
Two short: Memory ECC verification error.
3. Short: The system basic memory check fails.
Four short: system clock error.
5: CPU error.
6. keyboard controller error.
7. Short: The system real-time mode is incorrect.
8: memory error is displayed.
9. Short: the BIOS chip is incorrect.
One long, three short: memory error.
One long, eight short: the display data cable or video card is not properly inserted.
　　
2. If there is no alarm, the speaker may be broken. Follow these steps.
　　
A. Check the memory and use erasers to clean the plug-in. Change the slot to the test machine. If more than two memories are shared, try using only one memory.
　　
B. Check the video card. Check whether the video card is installed. Use an eraser to clean and install the plug-in. Then try again. Connect the video card to the monitor and try again to check whether the next self-check is performed. Try changing a video card if possible.
　　
C. Check the motherboard. First, place the motherboard on an insulated plane (such as a book or glass), because sometimes the chassis deformation will cause poor contact between the motherboard slot and the Board. Check whether there is any foreign body in each socket on the motherboard and whether there is any oxidation color on the insertion teeth. If one or two insertion teeth are different from other ones, it must be caused by oxidation or dust, please use a knife to scrape out the surface of the tooth, and then plug in the board to try the machine. Then, check whether the connection between the motherboard and the button is normal, especially the hot start button. Finally, use the discharge method to reset the BIOS. The method is to take down the button battery on the motherboard, wait for five minutes and then install the battery, or directly reverse the battery for two seconds and re-install the battery, and then try to see if it is normal. If you have the conditions to replace a motherboard, try.

D. Check the CPU. If the fault is caused by CPU overclocking, the above BIOS reset should solve this problem. If there is no overclocking, check whether the fan is normal. If there is no overclocking, try again.
　　
E. If the power supply is poor, this problem may also occur. Try replacing the power supply with conditions.
　　
F. If the above method cannot solve the problem, unplug all the hardware except the CPU, motherboard, power supply, memory, and video card, and try the machine to check whether the problem is normal. If it is normal, use fault symptom 4 below to solve the problem after eliminating the possibility of power supply and motherboard problems. If the test machine is abnormal, replace these components.

 

Fault symptom 3: After the device is powered on, the monitor has no image, but the machine reads the hard disk and determines through sound that the machine has entered the operating system.
　　
Analysis: this phenomenon indicates that the host is normal and the problem lies in the display and video card.
　　
Check ideas and methods: Check whether the connection between the display card and the video card is normal, and whether the connection is normal. If necessary, try to change the video card and monitor.
　　
Fault symptom 4: the video card and motherboard information are displayed after the device is started, but the self-check process stops when a hardware is started.
　　
Analysis: the information displayed on the motherboard and the video card indicates that the internal self-check has passed. The motherboard, CPU, memory, video card, and display should all be normal (however, the motherboard BIOS is improperly set and the memory quality is poor, unstable power supply also causes this phenomenon ). The problem lies in the possibility of other hardware. (In general, the BIOS self-check is not found, but you can perform the next self-check. If the self-check is stopped due to hardware reasons, the fault is serious and the hardware line may be faulty ).
　　
Check ideas and methods:
　　
1. To solve the problem, you can use the discharge method to modify the bios, or reset it to the factory settings (the steps will be found after you check the motherboard Manual ). Note that in BIOS settings, if the keyboard and mouse alarm item is set to stop self-check when a fault occurs, the keyboard and mouse are broken.
　　
2. If you can understand the self-check process, the BIOS generally stops working when it detects a hardware, which is highly likely to cause a fault, you can unplug the power cord and signal line of the hardware and start the system to check whether it can go to the next self-check. If yes, this is the hardware problem.
　　
3. If you do not understand the self-check process, unplug the power cord and signal line of the drive, hard drive, and optical drive, and unplug the sound card, modem, Nic, and other boards (excluding the memory of the video card ). Disconnect all external devices such as printers and scanners, and re-install them in the order of hard disks, soft drives, optical drives, boards, and external devices. After a hardware device is installed, start the system and try again, when a hardware fault occurs, it can be determined that the fault is caused by the fault.

Fault description 5: The system passes self-check, but cannot access the operating system.
　　
Analysis: the boot file cannot be found. If the hard disk is faulty, the operating system is down.
　　
Check ideas and methods:
　　
1. Check whether the hard disk is found during the system self-check. If you do not understand the self-check, you can try again with the boot disk, put the disc or boot floppy disk with an ultimatum boot, and change the BIOS settings to boot by the optical drive (soft drive. After you reboot disk A, press "C:" And press Enter.
2. If you can access drive C, the operating system is faulty. Reinstall the operating system;
3. If you cannot access drive C, the hard disk or partition table is damaged. Use the partition software to determine whether partitions can be performed. If partitions are not supported, the hard disk is broken. Otherwise, the partition table is damaged. Re-partitioning can solve the fault.
　　
Fault symptom 6: the system crashes shortly after it enters the operating system.
　　
Analysis: there are many reasons for the system to crash after entering the operating system. Here we only discuss the hardware issues, from the hardware aspect. The problem should be solved in terms of memory, power supply, CPU, and heat dissipation of various hardware.
　　
Check ideas and methods:
　　
1. Open the chassis, observe the graphics card, whether the fan of the CPU power supply is normal rotation, whether there is much dust on the heat sink, and whether the chassis is dirty (if the dust is cleaned, the power outage is required ). If the hard disk is hot by hand, it is slightly hotter than the hand. If it is hot, you can confirm that there is a problem with the hard disk.
　　
2. If the CPU is too frequently, Please reduce the frequency.
　　
3. faults caused by poor quality of power supply, memory, and motherboard can only be determined by switching them and then testing them.
　　
This article is about hardware faults. software faults and virus damages are not covered in this article. The most direct and effective method for hardware faults is replacement. If there are no actual conditions, you can analyze them from several sides and perform several inspection steps to narrow down the scope. This article focuses on the train of thought to give readers a repair step rather than a result.