The computer turns on for 1-2 seconds, the coolers on the PSU and the processor start up and cut down?

Question

Iron

In general, I worked on a PC, and it just turned off by itself instantly. Then, when I tried to turn it on, I found the following, when you press the power button, coolers on the PSU and processor start up and the button LEDs light up and after 1-3 seconds it turns off again, and sometimes it will work longer sometimes smaller.

Answer 1

Remove everything except the motherboard with the process and the PSU.
It is possible that the bios battery is dead.

Answer 2

Maybe BP. It is advisable to check with a known working PSU.

Answer 3

POST card and battery replacement to help.

Answer 4

Power supply 100%

Answer 5

Check with a tester if the voltage drops when turned on, or put a working power supply

Answer 6

Try moving the processor into the socket. Perhaps some contact is not included

Answer 7

PSU unequivocally, look at the conders, try another PSU.