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CPU Overheating. What's the cause?

Last response: in CPUs
September 3, 2004 4:51:17 AM

Okay. I'm quite peeved. My AMD Athlon was overheating like mad and I couldn't figure out why. So I guessed that the problem must be with the CPU, MB, or both. So I said "screw it" and bought an AthlonXP and new MB. Plugged it all up nicely and... wham. Overheated instantly. I went to the bios monitor on first boot-up and it was at 80 degrees celsius already and climbing until it shut off.

So. Now what?
I'm not ready to accept that it's coincidence that two CPU/MB's in a row have overheating issues like this, so it must be something else.

Could the power supply be causing this?


More about : cpu overheating

September 3, 2004 7:13:31 AM

how's the cooling in your case? For a CPU to hit 80c in the short amount of time getting into the bios, it sounds like your HSF unit isn't installed properly, or your fan isn't on.

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<font color=red>Cross him <i><b>off</b></i> then.
September 3, 2004 8:25:06 AM

Don't really think it's possible it's the case heat, considering the CPU heated to 100c in a matter of seconds after the CPU and MB having never been on before -- plus case temperature was only around 20c.

Right now I'm just wondering what could cause CPU overheats. The powersupply seems like the likely candidate -- plus it has to be something other than the current CPU/MB since it happened before, too. It also started happening on the last CPU after it had worked fine for months.
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September 3, 2004 8:46:55 AM

Try a new psu, you need one anyway.
September 3, 2004 4:33:56 PM

it sounds like your HSF unit isn't installed properly, or your fan isn't on.

Plus, what kinda thermal compound you using?

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September 3, 2004 4:50:38 PM

Have you checked the voltages your PSU is sending to your CPU? Check the vcore voltage.

<font color=blue>This guy here is <i><b>dead!</b></i></font color=blue>
<font color=red>Cross him <i><b>off</b></i> then.
September 3, 2004 5:08:07 PM

For it to reach 100° C in a matter of seconds, you heatsink can not be installed right, or not seated right. The only time I have ever seen a CPU heat up this quickly is one without a heatsink.

Sounds like you may want to replace your PSU and try it again, or even plug in an old one to test.

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September 3, 2004 7:52:09 PM

Even without a fan and heatsink, would a CPU actually heat up that fast in idle? Especially since A64's are suppose to be pretty cool CPUs.

Well I'm off to get a new PSU today and maybe some better cooling stuff just in case. I was going to try an older powersupply but it didn't have a 12v plug that I need.

Thanks for the help
September 4, 2004 12:14:10 AM

You can get adapters for that 12v plug you are talking about. Yes a CPU will heat up that quick without a heatsink, even at idle.

When it gets this hot, does your heatsink actually feel hot? I have a few random instances were certain programs, when run cause my temp sensor to go nuts, while one of these programs is open all the sudden my temps immediatly rise to 75-80° C instantly, and cause the BIOS alarm to go off. After I turn the power off, and right back on, the temps read right again.

May want to try feeling your heatsink to see if it is truely getting that hot, as your temp sensor could just be faulty. Don't let it run to long though, just in case it is actually overheating.

Hopefully its just the power supply, guess you will find out later today, huh? Let us know what happens.

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September 4, 2004 4:08:39 AM

Here's the update...

- Got a new 400w designed to assist airflow through the system.
- I redid the thermal compound, adding on "Ceremique High Density". My only concern there is that I'm not sure how much to apply. It was a pretty good layer on the CPU when I was done with it.
- I realized a blunder in installation and had forgotten to remove the shield from the backplate. That might have contributed something to it (don't know it's purpose)
- Added another in-blowing fan to the front coming to a total of:
1 x CPU fan
1 x MB fan
2 x front fans pulling in
1 x back fan pushing out (might add another one I have)
1 x inner circulation fan (in powersupply)
1 x back fan in powersupply

The temperature has finally stabilized but still a bit high. It's measuring in at around 56-60 degrees celsius w/ WinXP running and about a dozen low-impact background programs.

I'll try booting into safe mode just to see what happens now.
September 4, 2004 4:23:41 AM

the shield from the backplate? are you talking about the clear plastic cover that goes over the bottom of your HSF unit? If that's what you forgot to remove, that would explain a lot. Also, there's already a thermal pad on the bottom of the heastsink. if you didn't remove that, AND you used Ceramique on the CPU, that would explain why your temps are still a little on the high side. Not only would you have two different thermal compounds, but WAY too much. Go <A HREF="" target="_new">here</A> and read how to properly use the Ceramique. Also, clean both the core and the heatsink thoroughly with Goof Off and then at least 70% alcohol and make sure no residue is left behind. then follow the instructions on the website. Should lower your temps a bit.

<font color=blue>This guy here is <i><b>dead!</b></i></font color=blue>
<font color=red>Cross him <i><b>off</b></i> then.
September 4, 2004 4:32:09 AM

FYI, if you are using the MSI K8N Neo board, there is a bios update, that corrects an error in reading cpu temps.
September 4, 2004 8:38:31 AM

Yeah I had seen that elsewhere, too, but my bios is up to date w/ v1.1.
September 4, 2004 8:42:17 AM

It was a metal plate on the back of the MB, under the area where the CPU is mounted. It had a cardboard-like shield between itself and the MB by default that needed to be removed.

I didn't have GoofOff, but did a good cleaning of the heatsink and CPU and re-applied compound more appropriately.

Between everything it seems to be opperating mostly between 50 and 60 celsius which should be okay -- just a little higher than what it should be. I might try to get a better heatsink/CPU fan eventually. I think mine might not be up to par.

Anyway. It's good enough for now and running nicely.

Thanks for the help, everyone.