Computer Partially loses power.

[Kinohki]

Hello,
I'm new to the forums. I'm pretty good with PC's and rebuilt one from scratch however recently my PC has been giving me the weirdest trouble.

First off it seems the CPU will lose power yet the graphics card fan still spins and the lights on the motherboard are still on. The CPU will just stop and the PC does a hard shutdown, entirely turning off save the graphics card and motherboard. This is random.

I have a hunch it may be my power source as theres a small clicking in it which I'm assuming is the fan in it going out. Is it possible the power source could be overheating?

I've been using HW monitor to monitor the temps and the CPU temperature staying around 7-14 celsius. Occasionally it MIGHT spike up to 30 playing some games and stressing it but other than that it stays cool.

The motherboard hovers at around 37-42 mostly

And the graphics card anywhere between 30-50 depending on games, graphics resolution etc.

Windows 7 64 bit professional
8 gigs of Ram Corsair
AMD Fx 4100 quad core 3.6 ghz
Nvidia GTS 250

I also want to mention that I might possibly have a short in the power supply as sometimes the machine won't power back on unless I wiggle one of the large power cords. I've checked and made sure it's seated on the motherboard correctly and I'm 100% certain it is. The power source is about 4-5 years old now..

Those are the specs of my machine. If you need anything extra I'll add it in there. Thanks for the input guys.

 

[C12Friedman]

Welcome to Tom's Hardware Froums,
Your issues do sound as though related to a power supply problem. It seems you have more than one 12v rail and it's likely you've lost (or are losing) one of the 12v's.
Check to see if your PSU is in fact multiple 12v rail style, if so then I will suggest replacement. If it is a single rail type, then my suggestion may be invalid, I would want to know that also.
Hope it helps

 

[Kinohki]

Ah, thanks for the response. Apologies, but what exactly am I looking for per se? Admittedly I know nothing about power supplies other than it's a 500 or 550 watt supply.

How do I tell the 12v rails and such? Sorry for the noobish question.

 

[C12Friedman]

On the side of the power supply is a label that shows how the power is distributed and will have numbers like 5v and below it'll say 10A (amps). We're interested in the amperage numbers under 12v and if you have multiple 12v numbers like 12v 1, 12v 2 (I suspect you do), the numbers after the 12v indicate 'rails', each rail will have it's own amperage limit.
Hopefully the PSU is oriented so you don't have to remove it to see the label