Sign in with
Sign up | Sign in
Your question
Solved

Overheating CPU, baffeled

Last response: in CPUs
Share
July 27, 2009 7:41:57 PM

Hello All,

I'm having a bit of a CPU heating issue. Here are the specs

Mobo: ASUS P5N-E SLI
CPU: Intel Core 2 Duo E6750
CPU Heatsink: stock intel heatsink with 80 mm fan.
GPU: ASUS EN8500GT (single)
PSU: Antec Earth Watts 500
Cooling
2 80mm intake fans at front of case.
2 80mm outake fans at back of case.

The rig ran perfectly fine for about a 2 years. Until I moved.
The CPU is now idling right around 47 - 50 C . Under load it quickly climbs to 75 C.

My first thought was the heatsink got loose during the move. I was right, two of the pins had come loose from the board.

I cleaned the old thermal paste from the CPU and the heatsink using isopropyl and reseated the heatsink with a fresh dab of artic silver 5.

Now the CPU is STILL overheating, without any improvement. When I feel the CPU heatsink it is only slightly warm. I know this isn't a sensor issue because the machine will shutdown when the temp starts to get into the 80s. It seems the heatsink isn't transfering heat from the CPU properly. Has anyone heard of problems with the Core 2 duo heat spreader loosing contact with the underlying chip?

Additionally the Northbridge heatsink is getting really hot too, (ie I can't hold my finger to it without it burning me)

My diagnosis is a bad motherboard, any other ideas will be greatly appreciated.

a c 116 à CPUs
July 27, 2009 9:45:12 PM

A bad motherboard won't cause the Northbridge and the CPU to overheat. Is the CPU fan spinning faster when the CPU gets hot?

Since you moved, is there anything different at your new location, e.g., less airflow for the system or a warmer room?
m
0
l
July 27, 2009 9:53:29 PM

Yes, the CPU fan RPMs increase as the CPU gets hotter.

I don't have an air conditioner anymore, so the ambient temp at the new place is about 80-85, wheras before is was 75-80.

While I agree ambient temp is a contributing factor, it doesn't explain a 30 degree increase in CPU temp over 3 or 4 minutes when running more demanding applications.

I may try replacing the CPU heatsink/fan with something better and see if that helps.
m
0
l
Related resources
a c 139 à CPUs
July 27, 2009 10:04:52 PM

Check the bios and make sure for some reason that the CPU voltage has not been changed. Also it may help to turn off Qfan in the hardware monitor section of the bios.

That CPU runs extremely cool, built one for a friend and remember it being under 30 idle and in the low 40's load at stock speed(primed it over night). This was with the Q6600(slightly better then the stock) cooler, but you should be much cooler.

Sometimes that stock cooler is a pain in the ass to get on right, if you can remove your board, you can make sure the pins went all the way through.

Failing that, The Freezer 7 Pro is a great cooler for the price.
m
0
l
a c 116 à CPUs
July 28, 2009 1:44:15 AM

The CPU can't run below 30°C idle when it's that warm in the room; that would be an unrealistic expectation with the stock HSF. My Q6600 idles at 37-40°C (not all cores are the same) in a room at 22°C with the stock heatsink and a fan from a 541 (slightly better than the one that came with the Q6600). My E8400 in the same room idles at 42-43°C. Idle temps of 15-20°C above room temperature are to be expected with the stock HSF. If the room temperature is 30°C, then you can expect idle temps up to 45-50°C.
m
0
l
July 28, 2009 2:29:51 AM

Case ventilation can make a big difference when your living in a warm area. Take the side off the case and sit a 120mm fan on a small box or something similar so the fan is blowing directly on the cpu and chipset. Also put your finger on the heatsink while it's at 75 c to see if it's really that hot. Try it and see what you get.
m
0
l

Best solution

a b à CPUs
July 28, 2009 2:52:11 AM

> stock intel heatsink
> the heatsink got loose during the move.
> I was right, two of the pins had come loose from the board.


Read and heed:

http://www.supremelaw.org/systems/heatsinks/warning.htm


This is a very cost-effective solution:

http://www.sidewindercomputers.com/lgbowiscsp.html



MRFS
Share
July 28, 2009 4:18:48 AM

Ding ding ding, I think we have a winner. Thank you very much MRFS. Those cheap flimsy pins on the stock heatsink were wearing out. I just pulled the cooler again and one of the stupid clips broke off. Heatsink is now in trash .... good riddens. I'm going to order a new one, any suggestions (I don't want to spend more than 40 or 50 bucks.)

How about the Freezer 7 pro suggested by nukemaster? $31.98 with free shipping on newegg.
m
0
l
a c 139 à CPUs
July 28, 2009 3:34:35 PM

Do be aware that the Freezer 7 does use the 4 pin system, but there system seems to grip better.

If you are not overclocking to the moon, it should be good.
m
0
l
August 4, 2009 5:50:40 AM

Thank you all for your help! Especially Nukemaster for suggesting the Freezer 7 pro and MRFS for tracing the problem to the flimsy heatsink connectors.

Just installed my new Freezer 7 pro. I'm now idling at around 35-37 C. Under load I haven't seen it top 42 C yet.
m
0
l
!