Bizarre PC Issue (1 Viewer)

Is it not power supply if there's nothing+

It's fucked

Any lights on the motherboard?

check the internal power supply. The supplies can often go tits up. if you have a multimeter you can check to see if the 5 and 12v are being supplied from it, if no 5 and 12v then its the power supply. if 5 and 12v is OK the it could be one of your peripheral cards, check they are all seated ok. if all still knacker then you could be looking at your motherboard.

if the PC is one from ebay/or the like then I would start with the internal power supply as I have found they are nearly always under powered, you can pick up new PSUs online cheaply.

General Maintenance - is it dusty inside the PC, if so and every 6 months vacuum out the PC cleaning the fans and the cooling fan on the CPU.

good luck

In my experience every PC is salvageable, how much you're willing to spend on salvaging it is another matter. Prebuilt computers always come with the cheapest PSU they think they can get away with. Changing them is easy but quality PSUs are expensive which is why they don't fit them in the first place. You can often get away with a cheap replacement - provided it has the right power connectors, not all of them do.