help w/ hardware issue

[bshinkle]

I am stumped by a hardware issue I'm having with my main machine..

C2D 6750
Corsair HX 520
Gigabyte P35-DS3R
2G Crucial
Antec 900

It started out acting like a power supply issue. Random reboots were eventually followed by the machine refusing to post at all. When powered on, the fans come on after 3-4 seconds, spin for a few seconds, then die. This repeats endlessly, with no post.. Sounds like a bad p/s, right? Except that I swapped out the p/s into my kids' machine (P4) and it started right up..

So I replaced the mobo with a later rev of the same board, but the same thing is happening! I'm pulling my hair out here.

Ideas, anyone?

[Terminal]

It must be one of the peripherals. Video card perhaps?

[SmokeWatcher]

Check for a pinched wire coming off the PS. If those are OK then buy a new PS anyways. I've worked on hundreds of PCs that would do just like you described, but while it was unplugged to be moved, something had time to discharge and clear, causing the "fault" to go away. Since you already swapped the MB, I would say it is the PS.

EDIT: Since you didn't mention adding any new drives or cards when this began, we can assume (yea...I know) that you're not drawing more than the PS can deliver. That can cause intermittent problems also.

[bshinkle]

No new peripherals since initial build. I've disconnected the drives (3 seagate 300G) with no difference. I don't have another video card to try to eliminate that, but from the symptoms, I don't see how that would cause this issue.

I also considered that I was overdrawing on the p/s.. Here's what I have:

C2D 6750
3 Seagate 300G
DVD-RW
Geforce 7600 GT
floppy
Firewire add-on card

I've disconnected all the drives and the firewire card, with the same outcome.. So I don't think I'm overdrawing.

At this point, I agree, I'm RMA'ing the p/s (5 year warranty!)

[Fickey]

Do some research on your PS to see if others are having problems, too. I had an Antec Smartpower die, found lots of others had the same issue, and got Antec to RMA it for a different model. Also, not sure if this could cause exactly what you're observing, but might as well make sure all your cards, memory, & connectors are fully seated. Stuff like that can certainly cause a failure to POST.

[Bigbird999]

Like Fickey says! I had an Antec PSU that worked fine with one mobo but not another. Same symptoms as you. After pulling my hair out for a week or so, I emailed Antec and explained my problem to my surprise they RMA'd the 3 year old PSU and the new one worked fine.

BB