New Build Restarting

[mathiascali]

I've had my computer all up and running for a few hours but it has suddenly began to restart itself. It most often cuts out just after I log into Windows. It gives no message to indicate what could be causing the problem.

Specs:
Case: Cooler Master HAF 912
PSU: Corsair TX650 (650 watt)
Video Card: AMD Radeon HD 6870
RAM: Corsair Vengeance 8GB (2x4GB)
HDD: Western Digital Caviar Black 1TB
CPU Cooler: Cooler Master Hyper 212 Evo
Motherboard: Asus Sabertooth Z77
OS: Windows 7 Pro 64 bit

Could something be overheating? All of my fans are spinning okay and my BIOS shows the CPU having a 38 degree celsius temperature. The motherboard has the same temperature. Is there something wrong my RAM? Or PSU? Or GPU? Please help!

 

[manofchalk]

Usually random power cuts and restarts have to do with the PSU. Its a new unit from a good brand so it being broke isnt a huge possibility, but it might be.

Pop open the case and check if there are any power cables (particularly the 24pin ATX and 4pin CPU cables) that are barely plugged in.
Check if the power cable is plugged firmly into the PSU and the wall.
Check to see if anything is shorting out inside the case. This could mean you left extra standoffs behind the mobo, dont have standoffs outright or something is bridging the mobo to the case.

If none of that succeeds, may want to extract all the components out of the case and start breadboarding. Basically assemble to components on a non-conductive surface (a wooden table, mobo box) and see if it works. If it doesnt here, you can be fairly sure its a hardware fault.

 

[mathiascali]

I know that this PSU works because I've used it for months in a different computer before I put it in this one. I have re-plugged in all of the psu cables, making sure that they are plugged in firmly. No random restarts yet. Thank you for the response.

 

[mathiascali]

Best answer selected by mathiascali.