The computer can t start when you press the turn button, and the power light only flashes once and t

1. In the absence of specific circumstances, the motherboard is not so easy to break.

2. If it is a new machine, there may be problems with the motherboard, power supply, graphics card, etc. If you have used an old machine for a year or two, then you should not dust the motherboard first.

3. If there is no signal on the display, check whether the external connection is loose.

4. Can the graphics card be detected when the computer is turned on?

5. Whether the system has been damaged.

7. If the fan only turns once, there may be a problem with the motherboard or power supply. Unplug the power supply and use a wire to connect a green wire and a black wire of the motherboard power cord (either one is OK, remember to touch it, just see if the power supply fan rotates, if it rotates, it can generally be considered that there is no problem with the power supply. Disconnect all other connections and do it again.

8. If there is no problem with the power supply, it may be a problem with the motherboard.

The motherboard's 20-pin power plug is unplugged from the plug in.

If you have time to remove the motherboard, let's clean it up.

There may be problems with the motherboard, memory, and power supply, and it is up to you to see the specifics.

Disassemble the case, try to find a button cell battery on the motherboard, and then change the [jumper] closest to the battery (there are three pins two of which are connected together, what you have to do is to change the connection method), unplug the power cord, press the power button, and then the fan will turn down and stop. Restore the jumper to its original position, plug in the power cord, turn it on, OK

Discharge the BIOS battery (remove the battery, reinstall it or press F9 to restore the initial BIOS settings), it is recommended to plug and unplug the graphics card and memory, clean it up, and polish the gold finger of the graphics card and memory.

How to troubleshoot the failure of the computer without display when it is turned on (check whether there is a bulging capacitor).

Step 1: First of all, check whether the external wiring of the computer is connected, and plug in each cable again to see if the fault is eliminated.

Step 2: If the fault persists, then open the main chassis to check whether there is any excess metal in the chassis, or a short circuit caused by the deformation of the motherboard, and smell whether there is a burning paste in the chassis, whether there are burned chips on the motherboard, and whether the capacitors around the CPU are damaged.

Step 3: If not, then clean the dust off the motherboard and check if the computer is in good condition.

Step 4: If the fault persists, unplug the reset cable on the motherboard and connect it with other switches and indicator lights, and then use the change cone short-circuit switch to see if it can turn on.

Step 5: If you can't turn on the computer, then use the minimum system method, unplug the data cable of the hard disk and optical drive, and then check whether the computer can be turned on. Then connect the above devices to the computer one by one, when connecting a certain device, the fault will recur, indicating that the fault is caused by this device, and finally focus on checking this device.

Step 6: If the fault persists, the fault may be caused by devices such as memory, graphics card, CPU, motherboard, etc. Then, use the plug-in method, swap method and other methods to check whether the memory, graphics card, CPU and other devices are normal, and replace the damaged devices if there are damaged devices.

Step 7: When the computer is turned on without display but there is an alarm sound, when the computer is booted up, the system BIOS starts to POST (power-on self-test), when it detects a fatal error in a device in the computer, it will control the speaker to send out a sound to report the error. Therefore, there may be a fault that the power is turned on without displaying an alarm sound.

If the computer is turned on and there is no alarm sound, the fault can be checked according to the meaning of the BIOS alarm sound to check the faulty device to eliminate the fault.

If the fault persists, it needs to be repaired.