Power Supply Overheating

[Ghaz]

A while ago I was IMing my girlfriend to help her install an internal HDD. It ended up badly. The computer wouldn't turn on for some reason. She brought her pc round later (we live quite a distance apart). I concluded that the power supply had died for some reason. I replaced it with a spare one, and it worked. She's gone how now. However, now she says that her PC after a while slows down a lot, and things screw up (icons dissapear etc). She also notes that the power supply is running very hot. The friend who gave me the psu says that he used it for quite a while and it always ran quite cool. Now I can't get to the PC for a while, but I want to find out what is causing this.

Can an overheating power supply cause system slow downs? Could a faulty motherboard be causing these problems? What is my best course of action?

Thanks,

Ghaz.

Edit: The first power supply was 750 watt, the second was 650. I used a power supply calculator, and it recommended 406 watts.

 

[lasher]

You could check the Voltages being supplied correctly using BIOS or a software utility like AIDA64 formerly Everest.

Does the PSU have its own fan and if so have you checked it.

Never had a PSU blow or go faulty so cant really advise further mate.

 

[tinytomlogan]

HWmonitor will register volts too. Does sound like something is overheating though.

 

[Ghaz]

Right, thanks for your help guys. I'm going to get her to test the voltages. I just jump started the one I removed. Before, when in the pc, it would only spin up briefly. However, jump starting it, it spins up fine. Should I try testing the rails with a multimeter, and then try it in my PC?