Computer turns off and won't turn back on for a few hours?

voiidwulf

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Jun 11, 2012
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I bought a new PSU and GPU yesterday and after turning my computer on and running it for about half an hour the computer shut off. I did the paper clip test and came to the conclusion that the PSU was bad based on this and the fact that when I switched my old PSU back in it would let the system turn on.

So today I was going to go back to Memory Express and RMA it, but before leaving I decided to test it again and sure enough it started up. It had been running fine all day so I thought it was just a fluke but a few minutes ago it shut off again and now won't turn on.

Anyone know what the problem is? How can I RMA the PSU seeing as it will probably work fine for the people testing it since it will have been unplugged for a few hours?

Also I wasn't gaming during either crash so I don't think it's a heat problem.
 
Solution
The Corsair CX series PSU's are absolutely horrible for quality. They use very poor capacitors in them and I have swapped out at least 2 CX series PSU's for people due to them being defective. So even if the PSU is not bad I advocate for getting one of better quality. I understand the price on them looks great but in this case you only get what you pay with them.

Because they are so cheaply made it is possible that the PSU is not putting out the proper amount of Amps on the +12v rail for the HD 7970. AMD recommends a 550W PSU for these and I have found that a cheap 600w PSU will not put out and hold these GPU's.

If the PSU is still in the machine and it does it again, turn the switch off on the back of the PSU and unplug it for...

voiidwulf

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Jun 11, 2012
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Corsair CX600M 600W Modular
i7 3770
Some kind of Dell motherboard. I don't know the exact model without turning the computer on and checking CPU-Z, which I can't do right now.
16GB DDR3 1600 (Kingston if it matters)
AMD Radeon 7970 3GB (HIS if it matters)
 
The Corsair CX series PSU's are absolutely horrible for quality. They use very poor capacitors in them and I have swapped out at least 2 CX series PSU's for people due to them being defective. So even if the PSU is not bad I advocate for getting one of better quality. I understand the price on them looks great but in this case you only get what you pay with them.

Because they are so cheaply made it is possible that the PSU is not putting out the proper amount of Amps on the +12v rail for the HD 7970. AMD recommends a 550W PSU for these and I have found that a cheap 600w PSU will not put out and hold these GPU's.

If the PSU is still in the machine and it does it again, turn the switch off on the back of the PSU and unplug it for about 5 seconds the plug in, turn on switch and try to power up. If it does it is the PSU's over current protection kicking in shutting down the PSU for safety reasons. To try and kick the OCP you can stress the GPU and the CPU at the same time to draw as much from the PSU as you can to cause the issue.

You asked how can you RMA a PSU if it works when they test it? You would need to do some testing on your own first and If the OCP is kicking in then the PSU will only have issues when fully loaded so it will work on light loads. A 600W PSU will hold your system BUT only if it is of good quality. For safety I personally would do a 650W PSU to have some extra room for when the PSU ages and starts to not put out the full amount of wattage that it is rated for.
 
Solution

voiidwulf

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Thanks. The computer still won't turn on so I'll get back to you in a bit.

If you don't mind, off here what would you recommend for around $100? I thought Corsair would be decent quality because they're pretty well known but I guess not. Should have done research.
http://www.memoryexpress.com/Category/PowerSupplies
 
wow was just going to post this one as thermal takes are not that great. I just saw your post. Well if issues arise look in to this PSU EVGA SuperNOVA 750 B2 750W Bronze Modular Power Supply from the link you left.

Corsair does have good PSU's but the CX series is the there dirt cheap ultra low end PSU's. the RM CS and many others are great PSU's but the CX series are just crap.

Glad you have it sorted for now Good luck. For future reference right now the company's that have the best PSU's are Super Flower and ones they make for others (like the one I recommended), Seasonic and the ones they build of others like XFX, Antec ( but check the tier list for the really good ones) Corsair except the CX series, Rosewill Gold rated or over.

Some PSU reading material : http://www.tomshardware.com/reviews/power-supply-psu-brands,3762-2.html AND http://www.tomshardware.com/forum/324368-28-computer-power-supplies-guide
Here is the tier list and you will want a PSU from Tier 1 or Tier 2 : http://www.tomshardware.com/forum/id-2547993/psu-tier-list.html
 

voiidwulf

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Jun 11, 2012
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The EVGA Supernova 750 B2 was sold out. I actually tried to get that one originally instead of the Corsair. I got a 2 year no questions asked replacement warranty on the Thermaltake for $10 though so if it starts to show signs of failure I'll replace it.

Anyway, thanks for your help. It's been 8 hours or so and the computer still hasn't turned off despite heavy gaming so I think I'm good.