Intel Core 2 Quad Temp sensor defect
I just assembled a new media PC with a Core 2 Quad (Q9550) CPU (MB is ASUS P5E3 Premium). When I go to start, I get the error message CPU max temp overheating and when I enter BIOS setup and check system monitor, the CPU tem is listed as 97 C / 206.5 F. Now that is the temp right after startup and the temp doesn't go up or down. I even removed the oversized Scythe Orochi CPU cooler (this is big and expensive and looks like it will really cool, but the mounting brackets are a joke and really look cheap) and put on the Intel one just in case the Scythe wasn't connecting properly. Same temp in the bios monitor. Is the CPU defective? What can I do? I can just go with it and assume the temp is really OK, but it would be nice to know. Thanks for any help.
You need thermal compound, like Arctic Silver or Arctic Cooling MX.
Make sure the push pins are going through all the way to the back of the motherboard. Use a roll of duct tape for support and push hard.
Here are some installation instructions. Make sure you remove the plastic on the bottom of the heatsink.
I know that this post is old, but I had the exact same problem and corrected it. Mine was stuck at 206.5 degrees as well and wouldn't change from that. I also have the same exact motherboard and CPU as you did.
To fix the problem (in case someone else runs into this thread), you have to download the latest BIOS firmware. I downloaded the one from 5/09 that is in beta, I then booted up to the EZ Flash tool (I forgot the exact button it was now as I'm not at that computer, but it says what to press to get into the utility when going through POST or right after).
After this and the reboot, it found the CPU and detected it correctly. It no longer says CPU Over Temperature and you can see the temperature fluctuating in the Hardware Monitor in the BIOS.
Trust me, I did the whole cleaning of the heatsink and chip 4 times and gave up thinking it had to be something else. Everyone always gave the same solutions about doing this and I didn't see anyone say to update the BIOS. In this case, that worked and it had nothing to do with the heatsink.
Hope this helps for others that encounter the same issue.