CPU power connector problem

Fetttson

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Jan 25, 2009
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I just bought a new motherboard, installed it, and now my PC won't start. The lights and fans go on for about a second, and then stop. I disconnected everything except the CPU, and it still wouldn't start. I breadboarded it in case of a short, no dice. Then, I tried disconnecting even the CPU power connector. Everything starts up fine (except of course the CPU isn't running so it's useless).

I've never encountered this problem before, and couldn't find anything by searching. What does this mean? I'm pretty sure I have to RMA my motherboard, but thought I'd ask for advice here first. Thanks!
 

Alvin Smith

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Before you even do that much, you REALLY *should* read and religiously execute the document that I first linked to you.

I won't quote the Author, but *I* would agree, if he were to tell you that this doc, is a veritable oracle of VERY effective TS techniques .. AND .. I do mean that it will solve your problem, in the swiftest and most efficient manner, if you read and do all that, without skipping steps or making broad assumptions.

Standoffs under the mobo and cards and modules which are not FULL seated, are some leading causes of your symptoms (hint, hint) but, after quickly checking those two things out, you would do best to follow "the oracle", literally, and to the letter.

We could spoon feed and talk you thru it, but that will only slow you down, as we will likely be using that same doc as our own checklist (literally, or by wrote).

= Best-o-Luck = (but if you do - ^all^that^ - you prolly won't need luck)

 
If you replaced your motherboard, then that's the way to start. If everything works with your old motherboard and not the new one ...

As I said in my breadboard thread, it's a good way to test components before you put them into a case.
 

Fetttson

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Jan 25, 2009
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I did go through the entire thread Alvin posted before coming here.

System specs:
i7 920
Gigabyte X58AUD3R
Zalman ZM850-HP

Nothing else is connected right now, so the problem has to lie with one of those components. The motherboard is brand new, everything else is tried and tested.

I am breadboarding.

Like I said in my original post: while breadboarding with only the CPU and motherboard hooked up, I get a brief moment with lights and fans on, and then it shuts down immediately. On a whim, I unplugged the CPU power, tried again, and then everything started up fine. (Except of course there's no CPU...)

I don't need help going through a checklist to find the problem. I'm just unsure what it means if my system only starts up when the CPU power is disconnected. I tried to search for info, but couldn't find anything. I'm almost positive I'll have to RMA my motherboard, but I'm curious about what the problem is. Does this mean there's a short in the motherboard's CPU power connector somewhere?

Thanks guys.