Poss power supply issues

So I have this odd problem, where I will start my PC up and about 5 minutes in it will cold shut down. No blue screen, just flick off. The odd thing is that after that initial shut down, when it restarts it will run fine for a good while.

I just did a fresh Windows 7 install. The HD & GPU are less than 6 months old. Windows Memory Diagnostic and HD test is fine.

There's one thing that I don't understand; power supply values, here's what mine reads (from SpeedFan):

Vcore1: 0.91v

Vcore2: 3.01v

+3.3v: 3.31v

+5v: 5.05v

-5v: -1.99v

+5v: 4.97v (listed twice)

+12v: 11.97v

-12v: -5.86v

Vbat: 3.31v

GPU Vddc: 0.95v

The + voltages are within the regular tolerance levels, but the - numbers seem way off.

I suppose the question is what is -5v and -12v used for? The numbers for those seem way off. The -5v is listing 1.99 and the -12v is listing -5.86

Are these numbers being off (or any of the other numbers listed) indicative of the power supply just needing to be replaced?

(also for a note, I don't have a high end GPU, it's just a Radeon 6770, and the PSU is a 800w from an Anlienware machine, so I'm not overtaxing it)

A 800w PSU is total overkill and wasting energy, but in regards to your problem there could be a ton of reasons. Maybe you shorted your motherboard or your CPU / GPU is overheating. Open the case and check if every fan is working properly. If opening the case is already enough to make your PC run longer, than it's probably a heat issue. Make sure you don't OC your GPU / CPU.

If you have the chance to borrow another spare PSU from a friend, that's the second thing I would check. Also try to google the exact model of your mainboard to see if it's prone to that issue.

I don't think your RAM is at fault. RAM issues usually cause errors while running or the mainboard gives you a post code.

Btw, if you have to buy a new PSU a 500w - 550w model is more than enough, even if you plan on buying a second gfx for crossfire / SLI. I have a quality 450w PSU, overclocked 2500k and a GTX 780. My system is running full power rock stable for hours on end.

Assuming that the values coming from speedfan (I am not familiar with the speedfan program and how it gets its values) are correct then those values are way out of tolerance on your power supply. Based on those values I do not believe it is overheating but that is something you should check anyway. I would look into replacing your power supply. For refrence I have provided the DC voltage output regulation chart from the ATX 2.2 standards. If you are truly interested in finding out about power supplies and how they work then I would refer you to look at playtool.com and formfactors.org.

Cloulien

Comptia A+ and Network+ Certified Technician