Possible Bad PSU or mobo

[newskis]

I bought a bunch of new parts for my PC about a week and a half ago. What I got was a new mobo, cpu, ram, PSU, and windows 7. I put everything together and installed the OS, played some games, without a single problem. Then 3 days later when I went to power it up, all it did was spin the fans and attempt to post. But it would turn everything off about 2 seconds later, and repeat. I need to admit at this point that this is my second build, so theres still a good amount I dont know about computers. Most of my testing of various parts came from talking to people that knew better than me. Also, my mobo manual made it sound like I only needed one 4pin power, but after talking to people I found out I should have had both 4pins in. After two days of trying various things, I reset the cmos on a long shot. After that it worked again, so I attached a speaker to the mobo to listen to the beeps. It gave one short saying everything was fine. Then after 4 days of perfect working order, the same problem happened again.

 

From then on I've had to reset the cmos every day to get the computer up and running. I just want to say right now, that when my computer turns on, it runs with absolutely no problems. I've never had it turn off on me during use. All of the problems occurred with my computer being off for 10+ hours each night.

 

I've done an external build to rule out shorts on my case, that didnt change anything. I also bought a new battery for my mobo thinking that could be bad, that didnt fix it. I also tried setting the RAM voltages manually up to 1.65(default was 1.58), as told by my mobo manufacturer, no change. I had also tried my old PSU, which can run this, but that didnt work. Now in hindsight I tried that before figuring out the cmos thing. So last night I hooked up my old PSU and ran it for a while, then tried to turn on my computer today. And to my surprise it worked. I'm going to run it with my old PSU for the next few days to see if the problem comes back. Before today, I thought it was a problem with my mobo, but with my old PSU working, now it could be my new PSU. Right now I know somethings not right, and I dont know whether to RMA my mobo or PSU, or both.

 

I really appreciate you taking the time to read this long post. If anyone could shed some light on this for me, I would greatly appreciate it. At this point I cant think of anything else to do. I'm close to the point of just RMA'ing both my mobo and PSU. And in case you ask, I havent done the paperclip test because that makes me really nervous.

[RAM GUY]

I would make sure you have the latest BIOS for the motherboard and see if there is any improvement. You may also want to test the PSU in a different system to see if you can duplicate the same issues. If so, then the PSU should be replaced and you can Request an RMA. If updating the BIOS does not resolve anything and the other PSU consistently works, then the PSU should be replaced.