After the computer is turned on for three seconds, it is turned off and turned on for another three

Take a USB flash drive and reinstall the system.

Rebooting or shutting down for no reason, generally the CPU is too hot, viruses, dust, bad power supply, bad memory, too hot graphics card, and bad motherboard capacitors.

Install 360 security guard, boot has been pressing F8 to enter the safe mode to check and kill, now nine out of ten poisons on the Internet are Trojans, so the antivirus software can not detect the virus, it is recommended to install 360 killing, the heat dissipation is not good, reinstall the CPU heat sink, you can have poor contact, you can replace the CPU fan.

Reseat the graphics card and memory card, the main thing is to clean the dust near the CPU and memory, it is easiest to do this, or try to change the power supply (check your power consumption, sometimes the voltage is unstable).

When the CPU needs to supply a large amount of power when running large-scale 3D games and other software that occupies a large number of CPU resources, the power supply is not enough and the power supply is overloaded, causing the power supply to protect and stop the output. After the power supply stops out, the load is lightened, and the power is started again. Since the time for protection to recover is very short, the performance given to us is that the host automatically restarts.

When the harmonic content in the DC output of the power supply is too large, it will lead to errors in the work of the digital circuit, and the performance is a frequent crash or restart.

CPU workloads are dynamic, and so are the current requirements, and they require dynamic responsiveness. Some poor quality power supplies have a long dynamic reaction time, which can also lead to frequent crashes or restarts.

It may be caused by the processor's high temperature. It is also possible that there is a virus in your computer.

Possible causes:

1. If there is a virus in the computer, the anti-virus software will kill the virus or reinstall the system.

2. If the power supply or other hardware is damaged, the repair shop will repair it.

Third, the hardware is loosely connected to the motherboard, just plug and unplug it.

Fourth, if the software conflicts with the system, delete the software.

Fifth, there is too much dust, the processor is overheated, just clear the dust.

Listen to me: reinstall the system, it should be a virus.

There is a high probability of system problems, and it is recommended to reinstall the system.

1. It has nothing to do with whether the operating system is poisoned. It is mainly caused by hardware (power supply, motherboard, and graphics card), which will automatically restart when it reaches the step of reading the operating system. The second is caused by a problem with the switch of the chassis.

2. Unplug the power cord from the hard drive. Then test and troubleshoot. Frequent power failures and reboots make the hard disk prone to bad sectors.

A small number of such phenomena are hard disk failures (motors or circuit boards), but they should also be placed at the end, confirm other OK first, and then power on the hard disk (in this case, if it is a problem with the hard disk, you will know it at once).

3. Remove the side panel of the case, unplug the switch between the case and the motherboard, and the wire of the restart button. Then connect the two pins of the switch directly with tweezers (there is a definition on the side of the pin, which says power on or pwr on, regardless of plus or minus).If this is also a fault, you can troubleshoot the chassis switch.

4. Replace the power supply and see. Many of these phenomena are caused by miscellaneous inferior power supplies.

5. If you change the power supply and it still fails, change the graphics card.

6. If the graphics card is still faulty, pull out the memory stick, and wipe the gold finger with an eraser or alcohol (to remove oxidation).Then wipe the gold finger in the memory slot of the motherboard.

7. If you have tried all of the above and the fault is still there, it is the motherboard. It is most common for the regulated power supply part of the CPU to be damaged, resulting in a sudden power failure or failure to power on after powering on.

The brain will automatically power off and restart after two seconds of power-on, and the cause can be solved from the following aspects.

1. Power supply problems. If the motherboard indicator and boot indicator do not light up after pressing the power button, it is estimated that there may be a problem with the power supply, either the mains power supply is unstable, or the host power supply is broken.

2. The impact of dust accumulation. If the CPU fan has too much dust, it will cause the fan to fail to operate normally and cause the CPU temperature to be too high, once the CPU temperature is too high, the motherboard system will automatically start the self-protection system, resulting in abnormal shutdown or crash.

Solution: Open the chassis and use a brush and hair dryer to clean up all the dust accumulated by the fan, chassis, and motherboard.

3. Adverse effects of board contact. If the board is not in good contact, it will cause the computer to crash.

Solution: Remove the board (memory module, discrete graphics card, etc.) on the host, wipe the gold finger with an eraser, wipe off the oxide layer on it, and then plug it back in.

4. The system loses files.

Workaround: Restore the system backup.

It is estimated that there has been no dust removal for a long time, in this case, first turn off the chassis and open it, dust the chassis with a cooler or dry brush, unplug the memory or graphics card if necessary, use an eraser to wipe the gold finger, and then plug it firmly and then turn it on, and replace the chassis coms battery with a new one.

Two points that are easy to overlook:

1: The aging of the switch will also cause this phenomenon, you can buy a boot cable to replace it.

2: The motherboard will also have this phenomenon when it is damp, put the motherboard in a ventilated place for a week before use.

It can be restarted, it can be turned on.