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General discussion

only the cpu fan turns on? HELP!

Mar 15, 2004 12:59AM PST

I was re-installing Windows on 2 computers at once (in different rooms) and when I came back to my AMD Thunderbird, it was off and there was the light smell of smoke in the room... the computer won't turn back on so I left it off and unhooked the power.

Next day when I try to turn it on the CPU fan starts up (at a slower rate maybe) but nothing else does. The CPU fan is plugged into the Motherboard... so from this I deduce that the power supply must be ok (plus it's fairly new).

SO - is the problem my MotherBoard or the CPU?

The system's components were all being used before, this was just a re-install of windows. I don't have LED lights to tell me what's up and it's not returning any boot screen or error information and no beeps when I press the power button... only the CPU fan starts up.

I would think that if the MB was burnt that it wouldn't pass power through to the CPU fan... and without a CPU, you won't even get a boot cycle, right? That's why I don't think the problem is with the MB - I think it's the CPU that has burnt out.

Does this logic make sense to anyone who really knows? Please help me!!!


THANx
-dT

Discussion is locked

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Re:only the cpu fan turns on? HELP!
Mar 15, 2004 9:07AM PST

Your thought is OK, though not a guarantee that only the CPU is bad. Still could be motherboard or powersupply. Especially with the indication that the fan is slower. Sniff around the board and also look for burn signs. Take off the heatsink and fan and look at the top of the chip where the Thermalake or other seal was to see if it looks fried. It took less than 1 second for my AMD CPU to fry without proper contact with the heatsink. Make sure you use new Thermalake seal when you re-install the heatsink.

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Re:Re:only the cpu fan turns on? HELP!
Mar 15, 2004 9:18AM PST
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Re:only the cpu fan turns on? HELP!
Mar 15, 2004 10:04AM PST

The tbird cpu is a very demanding cpu. I would seriously consider a new supply. You should at least remove the cpu and check it. usually when it fries the bottom portion and/or the socket itself is very discolored. This being an older cpu and such there should some minor discoloartion as the tbird does generate alot of heat. But, since the fan still runs it appears the cpu maybe OK. Again the p/s unit comes to mind. The only other cause are a known problem with bad "capacitors" which can do blow or distort. Look for a leaky cap and/or distorted ones on the mtrbd. Being an older mtrbd. it may also have a separate VPM= voltage power module and these can go bad or lose their levels. Of course a bad p/s or VPM *may* cause the cpu to fry or simply crap out. In other words, you may find more than one problem and fixing half may cause the just fixed half to go bad as the remaining bad half takes it down again, so tread carefully.

good luck -----Willy