Very High Idle CPU Temps

[PotRoast55]

I have an Intel Core 2 Duo E8400 with the stock fan and a Gigabyte EP45-UD3P motherboard. I have applied Arctic Silver thermal compound after thoroughly cleaning the heatsink and CPU with the two ArctiClean solutions. Everything was done correctly; I made a very thin line of compound across the cores, and I mounted the heatsink/fan back onto it.

When I boot up and check the BIOS, my CPU temp starts out at about 35C and the internal temp is about 26C. But as I wait, both temperatures steadily increase, although it is still just in the BIOS. My CPU temp has gone up to 48C and the internal to 40C, and I turned off the computer. They probably would have gone even higher if I hadn't.

I have rearranged my three 120mm case fans to try to improve the overall internal temperature, but there is very little or no change.

If I try to boot into Windows, it will either crash before loading the welcome screen or shortly after. (But the CPU temperature doesn't go above 60 as far as I can tell, because my motherboard alarm doesn't sound.)

Here are my questions:
-Is the CPU the culprit, or could there be another underlying cause (perhaps with the motherboard)?
-If the CPU is the problem, will Intel accept an RMA without the original packaging and having removed the stock thermal paste?

 

[Reynod]

http://www.tomshardware.com/forum/273889-28-intel-cocket-install-heatsink

Check and see the 4 retention clips are down all of the way and locked (clicked) in ... watch on of the videos.

Also, boot into windows and run a third party cpu monitoring program like CoreTemp or HWMonitor as the bios might not be reading the sensor properly.

 

[PotRoast55]

Check and see the 4 retention clips are down all of the way and locked (clicked) in ... watch on of the videos.

The four clips are all pushed in.

Also, boot into windows and run a third party cpu monitoring program like CoreTemp or HWMonitor as the bios might not be reading the sensor properly.

I can't boot into Windows long enough to start an internet connection, let alone download and install a CPU monitoring program.

 

[Reynod]

Is this a new build or recently started happening after the system was stable?

 

[PotRoast55]

This was my first custom build. When I first built it August 2009, there were problems right away. It took me some time to figure out that one of the sticks of RAM was faulty. After I removed it, the computer ran smoothly for quite some time. The computer started having problems again about halfway through December. Two weeks ago, my friend came to help me, and he went into my BIOS and saw that the 12V rail of the power supply was fluctuating by significant amounts. So I RMA'ed it. I recieved the replacement yesterday, and the 12V rail is stable, but the problems persisted. He next suggested that because my CPU temp was so high that I reapply the thermal compound, and if that didn't work, to RMA the CPU, and if that didn't work, then RMA the motherboard. I just got back from the post office to mail the CPU.

This would be so much easier if I had extra CPUs and motherboards I could use to rule out the problem.

 

[Reynod]

This is a difficult one so let us know once the bits have arrived and your ready to try again.

 

[PotRoast55]

I got my replacement CPU, and luckily the majority of the problems have stopped. The CPU temp is down to 30 idle. The only problem I have now is that the computer will occasionally fail to boot into Windows and will restart. But once it gets to Windows, it's fine. Even if I knew exactly what causes the boot failure, it wouldn't be absolutely necessary to replace yet. It's certainly nice to have my computer back.

(Intel's customer support very good about the RMA.)

Since you're the only one who responded, reynod, you get the credit for helping to solve the problem.

 

[PotRoast55]

Best answer selected by Potroast55.