PC turns on then off then on then off every few seconds.

[Samurai_147]

My uncle's pc is turning on and off every few seconds he says it was working fine a few days ago but now the lights just turn on for roughly 2 seconds and then turn off and the cycle continues forever.

I reconnected all the cables including power supply cables inside the pc but no luck. Is it dead power supply or something else?

[ET_Explorer]

A weak cmos battery could be the culprit, try replacing it with a new one.