Computer randomly restarts to bios screen

[tenaciousk]

Hi everyone. I have been trying to figure out what is wrong with a buddies computer. I can get it to boot up. And sometimes it makes it to desktop. But withing a couple minutes it restarts at bios screen. Almost like something is tripping the motherboard.

Some things i have looked into that may help

It does recolonize the hard drive. I have got into test hardware.
The memory passed. The hard drive passed and the Processor. Everything in the hardware test passed.
Everything is hooked in correctly. I have unplugged all unnecessary things to see if it would run flawlessly. IT did not.

With only Power to motherboard it will just keep resetting to bios screen (with not hard drive or peripherals plugged in)

If anyone else has any ideas please let me know.

 

[Emerald]

What are the make and model of the PSU and MOBO?

What about the temperatures of CPU and GPU?

 

[tenaciousk]

I have tried multiple power supplies with the same results. The one that is in the computer now is a coolermaster 500 extreme power. I'm not sure about the motherboard. It is stock motherboard in an old pavilion with a Athlon 2 x2 Processor. I do not have a way of checking the temperature. It is my buddies computer. Would a overheated processor Cause a computer to restart?

 

[Emerald]

an overheating CPU or a bad CPU fan could lead to a reboot.

the BIOS show the temp or fan speed?