CPU over heat to 100

Before I have a CPU P4 2.8 775, got the problem, when startup motherboard post mesage say is overheat in CPU, than I change to P4 630 3.0 775, and turn to arround 50 degree, but after 1 weeks, it turn to same problem,while startup motherboard post mesage say is overheat in CPU!
I found a funny things that a power cord from the power supply(300w) which is connected to the motherboard fan is that correct?
The motherboard is Intel 915GAV, Ram 1gb kingston.Everything tested seems OK!
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Your wiring is NOT correct.  The CPU fan needs to be plugged in to the motherboard.  Look for 3 pin plug closest to CPU fan, plug in fan on that 3pin block.  The leads coming from the power supply are for an EXTRA fan, which will start if the main fan overheats.  YOu have been trying to run the system without any FULL-TIME cooling of the CPU by the CPU fan.  It needs to run 100% of the time.  The SECOND fan to go to the power supply plug, is designed to kick in if the CPU overheats, it goes to a 2nd CASE FAN near the CPU.  Hook it up right before you burn out the motherboard and CPU.
domdigAuthor Commented:
yes the CPU fan is plugged in to the motherbaord! I just saw a wire from PSU connect to the motherboard fan port!

Now I try to doing some stress test for that, the mainboard temp is 45 and the CPU is 61 is that high enough!
Sounds like you need to re-seat the heatsink and use NEW heatsink compound.  When you remove the heatsink, COMPLETELY clean off the old compound using some rubbing alcohol.  Then put new stuff on and be sure it covers the entire CPU...  then re-seat the heat sink.  See if that helps the temp issues.
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61 is MUCH too high, should be around 47 C, if you are above 55 C you are in danger of burning it out !!

Remove the wire from the PSU to the motherboard fan port, this is designed for a 2nd fan.  Do you ahve a case fan extra that you can plug in?  If so, put it on that second plug on the MB.  The main CPU fan should run all the time, full speed, and you should put silver paste between the CPU and the CPU fan.  Then on this second plug on the motherboard, put a PSU 80 MM fan and direct it at the CPU fan.  Your CPU is running TOO HOT !!!
domdigAuthor Commented:
61 is under the stress test!
but I think the motherboard temo is too high!
isn't it?

also is that 300W PSU is not enough?
My MB is at 36 C and the CPU is at 45C and it has been running flawless for years.  Under 50 for the CPU is good, and under 45C for the MB is good.  The 300W PSU is OK if you dont have extra Hard disks or 2 CD/DVD drives.  A good working 300 W PSU can support MB, 2 Hdds and one CD./DVD with no problem.

MAybe your CPU is already "stressed".  I worry about any CPU running over 55C, it is too hot to touch!!
domdigAuthor Commented:
hi Scrathcboy!
is it mean my CPU and motherboard is faulty?

I have really no idea how's the temp is good!
but I saw most of the computer is arround 54 something!

Also after the stress test, it turn back to aroung 50 is that OK?
Let the system cool 1 hour, take off CPU fan, check for thermal paste between CPU and fan base, silver is best.  Apply thin coating of thermal grease paste/silver.  Reattach CPU, make sure CPU fan is running all the time at about 5000+ RPM -- you hear whirring sound.  

Boot to system BIOS, check for "PC Health" choice, and go to that, monitor CPU temp for 10 minutes, it should stay below 55C, if not, the fan is not fast enough.  YES, 50C is OK, a bit high, but OK.  If it stays cool and windows does not boot, the CPU or motherboard could be overheated.

So yes, these high temperatures could have damaged the CPU or the motherboard.  A good windows boot will tell you if all is OK.  Good Luck !!  YES, 50C is OK !!

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domdigAuthor Commented:
but what about the motherboard is 45 ok?
Yes the motherboard is OK at or below 40C .  Mine is running at 30C right now, and that is very good.  Some CPU "artic silver" will probably help, but dont let the motherboard get too much above 40C.  Good luck.
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