Bad Mobo or PSU?


I recently started having a problem with my PC shutting down and struggling to turn on. The computer has been working fine for about a year now. Now when I try to turn on PC, the fans and lights start for about a second, then shut off, then automatically try again about 3 tries in a row, then shut down again, then starts over again. After several attempts the computer will stop trying, and neither the power switch nor the reset button does anything. I have to turn off the power supply or remove the power cable for a few seconds, then try again. Sometimes the power will then stay on, although the computer wont post until I reset the CMOS (which is a pain since I need to remove both video cards to reset the CMOS)

It started when I tried to take it out of sleep mode one day and it had trouble turning on and started showing the above symptoms.

I've taken out the video cards, and put it back together and it seems to run better for a short time. Then sometimes the computer powers on fine but wont post, so I have to reset the CMOS to get it to work again. It works again, I've even been able to play BF3 in SLI and it works fine. I shut the computer down, and the next time I go to turn it back on it struggles to turn on again. Same symptoms, computer turns itself on and off a few times within just a few seconds.

I've had it shut down on me in the middle of a game, and then struggle to turn back on, but sometimes once I get it going, it wont shut down at all even after a few hours of gaming. Shut the computer down and a day later it wont turn back on again.

Taking the power cables out of one of my video cards did not get my computer to start up properly. Same problems happened.

Normally I have extra components to test out certain things, but where I am now, I'm thousands of miles away from my extra powersupplies n stuff.
I plan to do more testing, like pulling it out of the case and putting it on a box with the min specs and seeing if it works fine, but right now I dont have alot of time.

It exhibits symptoms of powersuply failing or possibly a bad board or something shorting. I'm leaning towards bad p/s, but I'd rather it be the mobo, because thats cheaper lol. When I do get it running I still need to reset the CMOS. What do you guys think?

I realize I have quite a bit of load on my PSU, its only a year old, specs are as follows:

Intel i7 970 CPU
2 x Intel 160gb SSD
2 x WD VelociRaptor 300gb
2 x Seagate 1.5 TB
2 x Galaxy GTX 470 Video Cards
Asus Sabertooth X58 Motherboard
Corsair H50 Cooling System
4 x 120 mm fans
Antec Quattro 1000w Power Supply

If it's a bad PSU what would you guys recommend? I'm trying not to spend too much more than $200, Corsair HX1050 is what I'm looking at, its about $220. If its a bad board, I'd be ok with sticking with the same board. Guess if I'm patient black friday and cyber monday are coming up.

Thanks in advance.
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  1. The only way to know for sure is to start testing parts. Do you have another computer that you plug parts into? If so take the PSU and hook it up on the other computer to see if it still causes problems. If it does you know what the problem is. If not then it's probably the mobo.
  2. I've had a similar problem and I have done some Google searching on the topic. I found one user that had a RAM failure (on a new build) that caused a video failure from a shared RAM situation. He was blind to the issue because he had not installed a system speaker and couldnt hear the beep codes.

    In our case, the failure was gradual which (I believe) is due to a bad PSU. I bought a 500W PSU to replace a bad (?) 400W PSU and all is well....
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