Common troubleshooting methods for computers

Source: Internet
Author: User

Computer faults are common. Many faults can be diagnosed at the machine startup stage, especially hardware faults, you can determine the cause of machine failure by using the alarm sound and screen display information generated during the computer startup process. The following describes the common types and troubleshooting methods of hardware faults based on the computer startup process.

Start phase
The first step to start a computer is to turn on the power. The system conducts self-check and initialization under the control of the BIOS of the motherboard. If the power supply works properly, you should hear the power supply fan rotating, and the power indicator on the chassis should be on; three indicators, such as "Num Lock" on the hard disk and keyboard, are highlighted (and then extinguished ); the Monitor also emits a slight "beep" sound (which is much smaller than the degaussing sound), a sign of signal delivery from the display card. Common Faults in this phase are:

1. the fan is not rotated, and the power indicator is not displayed. It must be a power supply problem. Check whether the power plug behind the chassis is plugged in. You can pull it out and re-insert it. Of course, the power outlet, UPS fuse and other parts should also be carefully checked.

2. The power indicator is on, the screen is unresponsive, and there is no alarm. You should focus on checking the motherboard and CPU. At this time, the system is controlled by the BIOS of the motherboard. Before the basic self-check is completed, the computer will not trigger an alarm and the screen will not display any error messages. Check the following items:
(1) Check the Flash ROM chip on the motherboard and press it again after the power is turned off to make it in good contact;
(2) Check the BIOS chip of the motherboard, which may be attacked by the CIH virus or the BIOS upgrade may fail;
(3) Check the CPU, which can be determined by replacement;
(4) Check the memory stick. After the power is turned off, compress the stick so that the stick is in good contact or use the replacement method to further prove its quality;
(5) Check whether non-standard external frequency is used. If you use non-standard external frequencies such as 75 MHz and 83mhz, the poor-quality video card will be accessible. Standard external frequencies such as 66 MHz and MHz should be used;
(6) Make the chassis rough. After the reset key is pressed, the reset key cannot be restarted or the system is stuck to death, so that the reset key remains in the working state. You can use a multimeter or unplug the reset jumper on the motherboard and try again;
(7) Check the motherboard power supply. The power indicator is on, and the hard drive indicator is not on. There are two possible problems with the hard disk: one is that the hard disk data line is reversed; the other is that the hard disk itself has a physical fault and should be replaced.

Fatal hardware failure test
Core Components such as CPU, internal BUS, basic memory, interrupt, Display memory, and Rom are detected. At this time, the fault location can be determined by the number of "beep" sound sent by the speaker. Common examples include:
1. The computer sends a 1-minute alarm. Memory or motherboard error. Try another memory.
2. The computer sends a 1-2-minute alarm. The keyboard controller is incorrect. Check the motherboard.
3. The computer generates a 3-Minute Beep. It indicates that there is an error in the display or display card. You can turn off the power, check whether the video card and display plug are in good contact or use a replacement method to determine whether the video card and display are damaged. 4. The computer sends a short alarm, indicating that the Flash ROM, EPROM, or bios of the motherboard is incorrect or damaged. Use the replacement method to further identify the root cause of the fault. Note that the fault must be of the same model.
5. The computer sends a duplicate short response, indicating that the motherboard power supply is faulty.
6. The computer keeps a long beep. Indicates that the system has detected a problem with the memory stick. You should turn off the power to reinstall the memory stick or replace the new memory stick and try again.

Non-fatal hardware failure testing
The system sends a "beep" message indicating that the boot phase is normal and there is no fatal hardware fault, and it enters the non-fatal hardware fault testing phase. At this time, the screen shows the graphics card model, motherboard BIOS information, memory detection information and so on. If the self-check is interrupted at this time, you can determine the fault location according to the on-screen prompt:

The device detection information of the IDE interface is ::
"Detecting primary master... none
"Detecting primary slave... none
"Detecting secondary master... none
"Detecting secondary slave... Philips CD-ROM drive 40x maximum

It indicates that no hard disk is found for both IDE interfaces. This indicates that the hard disk is not connected or the hard disk is faulty. Check the hard disk from the following aspects:

① Whether the hard disk power supply has power or poor contact;
② Whether the hard disk interface line is reverse or loose;
③ Whether the CMOS settings are correct. Check the parameters "primary master", "primary slave", and "secondary master" in CMOS to see if they are inconsistent with the connected hard disk, the most reliable way is to set all the three "types" to "Auto ";
④ Physical faults of the hard disk. The "floppy disks fail40" error message is displayed under the detection information of the IDE interface device, indicating that the disk drive specified by CMOS is faulty. Possible problems include:

① There is a problem with the soft drive power supply, the power cord is not electric, or the interface with the soft drive is not in good contact;
② The soft drive data line is reverse and loose;
③ The CMOS settings are incorrect. Enter the CMOS check "drive a" type. If the type does not match the type of the attached soft drive, you should reset the settings. Currently, the values are "1.44 m 3.5 in .";
④ Soft drive physical faults. CMOS battery state low CMOS battery voltage is too low, should be replaced. BiOS check and read errors in CMOS Checksum Failure CMOS should be re-run CMOS setup Program .
CMOS System option not set ~
The CMOS system is not set.
CMOS display Type Mismatch
The display type in CMOS is not consistent with the actual measurement. You should reset the settings.
The display switch not proper board has incorrect display mode jumper settings.
The keyboard is lock... unlock it keyboard is locked. Open the lock and reboot the system.
Keyboard error keyboard timing error.
KB interface error keyboard interface error.
The master memory on the CMOS memory size mismatch board is different from that set in CMOS.
<br>
<br>
<br>
<br>
<br>
<br>
<br>
<br>
<br>
The address decoding circuit on the address line short motherboard is faulty.
The DMA #2 Error Memory directly accesses the DMA Channel 2 error.
The DMA #1 Error Memory directly accesses the DMA channel no. 1.
The DMA error DMA controller is bad and should be replaced. Nywe
No Rom basic when the Boot Sector on the drive or hard disk cannot be found, BIOS attempts to enter the rom basic program failed.

The system boot floppy disk in the diskette boot failure soft drive is broken.
An error occurs in the boot program of the floppy disk read by Invalid Boot Diskette. Change the disk and try again.
Memory parity error on board parity error motherboard. The error address is shown in the second row in the format: addrhex = off board parity error motherboard I/0 bus expansion slot memory expansion card memory parity error, error address is given in the second row, format: addrhex = parity error? The Memory parity is incorrect, but its address cannot be determined.

The error message "keyboard error or no keyboard present" is displayed, indicating that the keyboard is faulty. Generally, there is a problem with the interface connection between the keyboard and the motherboard. After shutdown, unplug the keyboard and re-plug it. If this information still appears after the reboot, it indicates that the keyboard is faulty.

 

Contact Us

The content source of this page is from Internet, which doesn't represent Alibaba Cloud's opinion; products and services mentioned on that page don't have any relationship with Alibaba Cloud. If the content of the page makes you feel confusing, please write us an email, we will handle the problem within 5 days after receiving your email.

If you find any instances of plagiarism from the community, please send an email to: info-contact@alibabacloud.com and provide relevant evidence. A staff member will contact you within 5 working days.

A Free Trial That Lets You Build Big!

Start building with 50+ products and up to 12 months usage for Elastic Compute Service

  • Sales Support

    1 on 1 presale consultation

  • After-Sales Support

    24/7 Technical Support 6 Free Tickets per Quarter Faster Response

  • Alibaba Cloud offers highly flexible support services tailored to meet your exact needs.