PC Hardware

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Computer powers up...then back down; no POST beeps or anything

by John Gafnea / June 5, 2004 6:21 PM PDT

Whenever I start my computer the everything (except the small fan on the motherboard itself, that hasn't worked for a while though) starts up like normal for about 3 seconds. Then it all shuts back off. The first time this happened I played with the battery on the motherboard a little bit and after that the computer went back to working, but only half the time. I decided that it was the battery so I bought a new one and put it in and then the computer started up fine ~5 times. Now (after going ~8 hours off) it's doing the same thing it did before.

Anyone know what this is? Bad motherboard?

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Re:Computer powers up...then back down; no POST beeps or anything

Hi John,
If, by "the small fan on the motherboard", you mean the fan on the CPU heatsink, you are heading for a burn-up.
That fan MUST start with the computer power-up, and MUST run all the time, to keep the CPU temperature in limits.
It sounds as though the motherboard or CPU overheat protection is shutting down your machine to prevent the CPU from cooking.

Roger

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Re:Re:Computer powers up...then back down; no POST beeps or anything

Here's my mobo:

http://home.comcast.net/~johngafnea/board.jpg

The CPU heatsink (located bottom left corner) works fine. The small black plastic fan (a little bit left of center) is the one that isn't working (and hasn't been for a while).

I guess I'll try to get some more fans going in my room.

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Re:Re:Re:Computer powers up...then back down; no POST beeps or anything

Thats the chipset fan - the motherboard will automatically power down when it detects that the fan isn't running - just use a CPU fan(if u have one spare - it'll require some creative mounting).

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Re:Re:Re:Computer powers up...then back down; no POST beeps or anything

That fan was there because the chip could be damaged by overheating. You just let it go and that may have resulted in the chip burning up. While you can replace that fan, it is more likely you have a damaged chip and a new fan won't help at all.

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Re:Computer powers up...then back down; no POST beeps or anything
by Willy / June 6, 2004 11:33 PM PDT

Replace that chipset fan, NOW. If you're lucky you'll be able to continue on. If damage has already been done, it will continue to shutdown but at longer intervals before doing so even with a working fan. Otherwise damage is too great and time to pitch the mtrbd. in the trash. Let it be a lesson not to be repeated. Sad

good luck -----Willy

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Re:Re:Computer powers up...then back down; no POST beeps or anything

Okay I replaced the chipset fan and that immediately fixed the problem. Now though it's going back to doing what it was doing...about half the time.

What's weird is if I unplug all drives, then it starts up fine everytime (althought obviously it tells me no drives are found). Would this indicate a power problem?

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Get ready to pitch that MB

As everyone has been saying...your failure to fix your fan when it first quit has PROBABLY damaged your motherboard. So...get ready to say goodby to it. BUT BEFORE YOU DO...download a freeway MB diagnostic program (Use TUCOWS as a source) and find out for use what is working and what is not. Perhaps you have laying around somewhere the install/driver CD that came with your motherboard/computer. The manufacturer may have included a diagnostic program on that CD for just such a time like this. Check it out. God's Speed!

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(NT) my PC is dead, no POST, no beep.The HDD lamp is on
by tofakos / January 8, 2009 3:10 AM PST
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