Hardware issue - been trying to solve for weeks now

[tiger131]

Alright, this is a toughie. I work at a PC Repair shop and no one here seems to have any more ideas than what we've already tried. Basically 90% of the time my PC will hang before it gets to the post or at the post. It does not beep, just hangs with all the fans spinning at 100%.

Athlon 64 x2 3800+ (stock speeds)
ASRock 939dual SATA II
2x512 Generic ddr400 memory
X1800XT 256mb
2 WD HDD, 2 optical drives
Antec Truepower 500W (18/17A on 12v)
(I also have a 550W Mushkin b/c I bought it thinking my PS went out, that puts out 20Ax2 on 12V)
Also BIOS settings have all been set to factory settings.

Ive tested the entire hardware system with a P.H.D.v2 hardware diagnostics and everything came back fine without a hitch. Tried swapping out every part except for a motherboard and cpu so far.

I just wanted to get any other opinions before I RMA this board, I'm about to rip it out and put it on the test bench to make sure, but maybe someone else has some ideas I could try.
Thanks a lot

 

[miahallen]

2 things, you probably already tried, but you didn't mention.

1) use BIOS reset jumper

2) re-apply CPU thermal grease, and re-seat CPU cooler

Otherwise, I'd say you're safe to initiat the RMA

 

[dolynick]

It may be your power supply. I've lost count of the times I have seen a workstation with a failing (but not dead yet) power supply turn on but fail to post (just a blank screen, no beep errors). About 95% of the time with those, changing the power supply is the solution.

If you have or can find a spare power supply, just pop it in and see if she goes.

-dolynick

 

[tiger131]

(I also have a 550W Mushkin b/c I bought it thinking my PS went out, that puts out 20Ax2 on 12V)
Also BIOS settings have all been set to factory settings.

Maybe I should've mentioned that I have indeed tested with a brand new 550W mushkin that I said I bought. Both do the same thing. I'm at the office right now and I tore it down to the test bench with nothing in it and it posted right away. Put on stick of ram in, worked, tested that in all 4 slots, worked everytime without a hitch. Put other stick in by itself and tested in every slot, no problems whatsoever. Tried combinations of 2 sticks in every possible combination, worked every time. Put HDD and videocard in, no problems either (this is with the Antec 500W p/s). There are no busted capacitors on the motherboard and I've double checked all the jumper settings. Im just really stumped on this. This is why I don't want to RMA b/c I think its something so simple that I'm looking too deep possibly. Maybe a short when its in the case?

 

[dolynick]

Apologies, I completely missed the stating that you'd tried a new PSU already in your original post. My bad.

If it's working torn down on the bench then that is an odd one. You may be right that its a short when in the case, touching somewhere or something like that. Unusual, but possible.

Another possibility is that you didn't have something seated right when it was all inside the case, though one would think you'd get some kind of beep error.

I would rebuild it in the case again and just see what happens.

-dolynick

 

[tiger131]

No problems, I know it was a lot of words and its easy to kind of skip over some things.

The weird thing is, sometimes it would start up while it was in the case. I had reseated everything before to try to get it to work. So im going to just rebuild it in the case, and if it does it again, use one of the empty cases we have here and hope for the best. Appreciate your thoughts

 

[dotcom012]

to follow up on what someone said, i had a comptuer what we built outside of a computer case and everything worked fine, i didn't think twice about it, so i slapped everything in a case and let someone have it, well they called me back saying, "All i hear are the fans, nothing happens", upon getting the computer back i tried everything you mentiond above, i didn't know what else to do, well needless to say, it was a short in the case, everytime the motherboard was in there some of the pins would touch the case causing it not to do anything, i fixed this by taking a very thin piece of packing material and placing underneath the motherboard while i was screwing it in, this fixed everything, comptuer now works fine. See if that helps.

 

[tiger131]

Thanks a lot, haven't got the time to test it yet, I forgot some of the P/S cables at home (all I brought with me was the 6pin PCI-E plug - doh!) But I will definitely try that. When you say packing material, what exactly are u talking about? Foam was my first guess.

 

[dotcom012]

Yea, i used a the foam that was with the motherboard when i purchased it, i just put it under the board and screwed it in, no problems so far from it.

 

[Zorg]

They also have different lengths of stand offs. This is also really obvious, but just in case you overlooked it, check the number and position of the standoffs. I know it's really obvious, but that's what makes it easy to miss.