No POST, No Beep(s), Swapped EVERY part

[slvrstang]

So I have a p5Q mobo, E6550(stock), crucial ram, PC p&c 350w PSU and a ati video card of some kind.

The PC began to become flaky and not posting randomly, then one day it wouldn't post at all. I replaced ALL the parts one at a time and it would post, then not post, then post, then not post seemingly random. It doesn't even care what parts it has in it.

So I went to the store and bought a new motherboard, cpu, psu,video card and ram. Now guess what...still won't post reliably. I've checked all the jumper settings, I've tried all kinds of ram configurations. I've tried literally everything I know how to do on PC's and that's saying a lot. THis is 100% new. The only old parts left are hard drives.(not important to posting) It won't post w/ or w/o the optical/hdds.

Also, just to clarify, by no post I mean the computer turns "on" but doesn't give the VGA beep nor display anything on the screen nor play the windows turn on sound after 2-3 minutes. The fans turn on.

If I take out the vid card I don't get a no vga beep, if I take out the RAM I DO get a no ram beep.

I'm completely stumped. It's like having a car transmission fail and you buy a new car only to find the new car's transmission is broken in EXACTLY the same way and it never had ANY interaction with the other vehicle.

I've measured BOTH the old and new PSU's rails with a voltmeter and they're all withing 1-2%. I've tried jumping the PW_Switch jumper instead of using the front button. I've tried booting outside of the case to eliminate possible shorts. I can't think of anything else to try.

Extremely frustrated.

 

[Hefemeister]

Have you checked to make sure the board is not some how grounded on the motherboard tray?

 

[thirdshiftdj]

Does the CPU fan turn on also or just the aux fans? At this point I would try anything that you haven't thought of like using a different outlet thats not on the same breaker. It always ends up being the retarded things that cause it not to work. Sounds like a stupid idea but try it anyways

 

[S0ULphIRE]

If you've tried two totally different machines and they come up with the same error I'd say try a different power socket or power cord.
It's the only common factor in both builds, so try moving the pc to a socket you KNOW works (e.g. the one your tv is plugged into).

 

[slvrstang]

Tried both computers at two different houses plugs. Tried them not on the mobo tray, just laying on a table.

They work...sometimes. But sometimes they just won't post at ALL for a few days. then I push the button, boom on. It's ridiculous. All the fans come on, including the mobo fan.

The southbridge seems to get pretty warm when it gets "stuck" in the nopost on mode. Too hot to touch, I'd say 50C+.

 

[GreenMachine]

73 percent addctd

 

[Asylum]

What kind of PSU's are you useing?

 

[Jorsoft]

I've had this happen to me before with a new build, worked fine for a couple of days and then no POST or beeps. I swapped out most of the parts for identical ones and it persisted. Turns out it was the memory in the end, it was an incompatible set of sticks. The specs were fine but it wasn't on the compatibility list on Asus' website and swapping for ram that was solved the issue. Might be worth looking into.

 

[slvrstang]

I've had this happen to me before with a new build, worked fine for a couple of days and then no POST or beeps. I swapped out most of the parts for identical ones and it persisted. Turns out it was the memory in the end, it was an incompatible set of sticks. The specs were fine but it wasn't on the compatibility list on Asus' website and swapping for ram that was solved the issue. Might be worth looking into.

This seems to have been the solution. I bought a stick of Patriot ram (was using Crucial Ballistix before, tried 2 different types) and the system booted and is rock solid.

Bummer for me, wasted a LOT of labor time on this