Can a faulty power supply destroy ram and video card?

[dognabbit]

Can a faulty power supply destroy ram and video card?

 

[jiffylube1024]

Yup. A bad PSU can take out just about anything in your case. They can even catch fire (though good brands typically don't).

Most notorious are generic, cheap ones because of the poor voltage regulation circuitry. A good PSU will have +3.3V, +5V and +12V rails that are well within 5% of spec. Generic PSU's can be much more flakey and are often all over the map.