[SOLVED] PC turns on when CPU power cable is unplugged

[iuliandubee]

Hello, so i have an old computer which I want to revive for basic tasks (like browsing). Some years ago it had a problem where the PC turned off by itself and i couldn't turn it on back again, at that time i wasn't bothered about this because i was changing my computer. Now i got my computer out from the attic, cleaned it, changed the thermal paste, every power cable was connected, but sadly the computer won't turn on, i thought it was from the power supply, i had a spare PSU lying around and changed it with the old one, but the problem still persists. I unplugged the CPU power connector and the PC turned on with the spare PSU. I tried to breadboard the old power supply with a wire and it turned on, so it wasn't the problem coming from the power supply. Is it obvious that the mobo is dead, has blown capacitors or the CPU is broken?

 

[R_1]

Reading that my first thought is to remove the power switch and manually jump start the computer by shorting the power pins with a screwdriver. My hope is that the power switch is faulty and simply replacing it will address the issue.

if the system does boot up properly even if sporadic it indicates the motherboard is functioning.
you can look for swollen capacitors or leaking capacitors

if you find any damaged capacitors then yes the motherboard will need replacing to get the system functioning.

 

[iuliandubee]

Reading that my first thought is to remove the power switch and manually jump start the computer by shorting the power pins with a screwdriver. My hope is that the power switch is faulty and simply replacing it will address the issue.

if the system does boot up properly even if sporadic it indicates the motherboard is functioning.
you can look for swollen capacitors or leaking capacitors

if you find any damaged capacitors then yes the motherboard will need replacing to get the system functioning.

The power switch works, but the pc doesn't turn on when the CPU power connector is plugged in. I will try then to look after bad capacitors, thank you for replying on my post