computer can not start how to do? Recently, many computer users have been asking this question. Most of the friends who use computers should have encountered that the computer can't be started, and they are helpless in this situation. So how to solve the problem that the computer can't start? There are many reasons for this. According to the diagnosis and treatment of the fault phenomenon, understand the process of computer startup, the fault is judged. Below we start diagnosis and treatment according to the fault phenomenon, first from simple to copy to eliminate, first learn to observe, then think, this is also the most basic to solve computer problems. The principle (how to set the boot entry). Phenomenon 1: The system can't start at all. When the power indicator is off, the sound of the cooling fan is not heard. At this time, first check if the connection is not connected, there is no power line loose, if not, it can be basically determined that the power supply is partially faulty. Check: Whether the power cord and socket have power, whether the motherboard power plug is connected, whether the UPS is powered normally, and then confirm whether the power supply is faulty. The simplest method is the replacement method. However, it is impossible for the general user to have spare parts such as power supply. You can try the following method (note: be careful): first connect the hard disk, CPU fan, or CDROM, then connect the ATX motherboard power plug with one wire to connect the two pins (put one side of the plug to the other, The upper pin is the fourth from the left and the third pin from the right, the direction must be correct.) Then turn the ATX power switch on. If the power fan is turned, the power is normal, otherwise the power supply is damaged. If there is no problem with the power supply, directly short the jumper of the power switch on the motherboard. If it is normal, the power switch of the chassis panel is damaged. Phenomenon 2: The power indicator light is on and the fan is turned, but the display has no obvious system action. If the computer is used for a long time, it may be caused by loose memory or too much dust. You can remove the memory module, clean it up and install it. The general problem can be solved. If it appears on the newly assembled computer, it should be the first. Check if the CPU is plugged in or replace the CPU, and the CPU of the computer being used is damaged (except for human damage). When it is damaged, it is usually burnt. If you have just upgraded the BIOS or encountered a CIH virus attack, this is To consider the BIOS corruption problem (the BIOS is inexplicable damage is also there), the method of repairing the BIOS is not repeated in many magazines; after confirming that the CPU and BIOS are no problem, it is necessary to consider the CMOS setting problem, if the CPU frequency setting is not Correctly, this kind of fault will occur. The solution is to clear the CMOS information. It is necessary to discharge the CMOS. Generally, there is a CMOS discharge jumper on the motherboard. If the jumper is not found, the CMOS battery can be removed. Do not lower than 5 minutes, then restore the jumper to the original state or re-install the battery; if the CPU, BIOS and CMOS are no problem, consider Power problem: The PC power supply has a special output signal called POWER GOOD (PG) signal. If the low level duration of the PG signal is insufficient or there is no low time, the PC will not be able to start the 2500 yuan computer configuration list. If the PG signal is always low, the PC system is always in the reset state. At this time, the PC also showed a black screen, no sound, and other crashes. However, this requires professional repair tools plus some maintenance experience. Therefore, it is recommended to use the replacement method; if there is no problem with the power supply, check for short circuits and ensure that the surface of the main board is not in contact with the metal (especially the mounting point of the chassis). Take the motherboard and power supply out of the chassis and place them on the surface of the insulator. If it can be started, it means that the motherboard has a short circuit. If it still cannot be started, consider the motherboard problem. The motherboard fault is more complicated. You can use the replacement method to confirm and then replace the motherboard. Phenomenon 3: The power indicator light is on, the system can start, but the system stops at initialization, and you can hear the screaming sound (no video): The faulty part can be judged according to the peaking code. Ccid_page/Award BIOS 1 short sound: Indicates that the system starts normally. Indicates that the machine is ok. 2 short sound: Explain that the CMOS setting is wrong and reset the incorrect option. 1 long 1 short: Explain the memory or motherboard error, try another memory stick. 1 long 2 short: indicates that there is an error in the display or display card. Check if the graphics card and monitor plug are in good contact or use the replacement method to determine if the graphics card and monitor are damaged. 1 long 3 short: Description of the keyboard controller error, should check the motherboard. 1 long 9 short: Description of the motherboard flash RAM, EPROM error or BIOS damage, replace the flash RAM. Repeat short sounds: There is a problem with the motherboard power supply. Uninterrupted long sound: The system has detected a problem with the memory module, reinstall the memory module or replace the new memory module and try again. AMI BIOS 1 short: The memory refresh failed. Replace the memory module. 2 short: Explain that the memory ECC is wrong. Set the memory ECC check option to Disabled or replace the memory in CMOS. 3 short: Indicates that the system basic memory check failed. Change the memory. 4 short: Indicates that the system clock is faulty. Replace the chip or CMOS battery. 5 short: Explain that the CPU has an error. Check if the CPU is plugged in. 6 short: Description of the keyboard controller error. The motherboard should be checked. 7 short: Indicates that the system is in real mode error and cannot be switched to protected mode. 8 short: Description shows a memory error. There is a problem with the display memory. Try replacing the graphics card. 9 short: Explain the BIOS chip check and error. 1 long 3 short: Explain the memory error. Memory is damaged and replaced. 1 long 8 short: Description shows a test error. The monitor data cable is not plugged in or the display card is not plugged in. Phenomenon 4: The system can be started, there is a video, and a fault prompt appears. At this time, the fault location can be judged according to the prompt. The following are some common fault prompts: First, the prompt "CMOS Battery State Low"; Cause: CMOS parameters are lost, sometimes can be started, use a period of time after the crash, this phenomenon is mostly caused by insufficient CMOS power supply. For different CMOS power supply methods, take different measures: 1. Welded battery: re-weld a new battery with a soldering iron; 2. Button battery: direct replacement; 3. Chip type: replace the chip, It is best to replace it with the same type of chip. If the battery does not last long and the same phenomenon occurs, it is likely that the motherboard is leaking. You can check whether the diode or capacitor on the motherboard is damaged. You can also use the external battery with a jumper. However, these require a certain hardware maintenance basis. . Second, the prompt "CMOS Checksum Failure" CMOS BIOS check and read error; prompt "CMOS System Option Not Set", CMOS system is not set; prompt & ldquo; CMOS Display Type Mismatch & rdquo;, CMOS display type settings and The measurement is inconsistent; the prompt “CMOS Memory Size Mismatch”, the main memory on the motherboard is different from the one set in CMOS; the prompt “CMOS Time & Date Not Set”, the time and date in CMOS are not set. These need to be reset to CMOS. Third, the prompt "Keyboard Interface Error" after the cause of the crash: the keyboard interface on the motherboard can not be used, unplug the keyboard, re-insert and can start the system normally, after a period of use, the keyboard does not respond, this phenomenon is mainly multiple plug The keyboard causes the keyboard interface of the motherboard to be loose. Remove the motherboard and re-solder it with a soldering iron. It may also be a plugged-in keyboard, causing a fuse on the motherboard to be broken (marked as Fn on the motherboard). 1 ohm /0.5 watt resistor can be used. 4. The self-test process is interrupted at xxxK Cache. This means that the Cache on the motherboard is damaged. You can set the “External Cache” option in the CMOS settings to “Disable”. Similarly, if there is an interruption in self-checking the motherboard components, the component can be considered damaged. The solution can generally be shielded in CMOS. If the component cannot be shielded, it is better to replace the motherboard. Well, about the computer can not start how to do, the computer can not start the analysis and solution for everyone to introduce here, according to the steps given above to eliminate one by one, generally can find the problem that can not start the computer. Only by determining which component caused the computer can not start normally, we can only understand, judge, solve!