mrbob_21

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Dec 10, 2009
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Hi,

I have an Intel DQ45CB MB with a Q9650 Quad CPU. A couple of times in the past the CPU fan started to run at full speed so I reseated the RAM and CPU fan/heatsink and all would be fine for a few months.

A few weeks ago the CPU fan started to run at full speed again. I did the usual but it still ran at full speed. When I checked in BIOS, the motherboard was showing as overheating and the board voltages were out of spec. I installed Intel Desktop Utilities which confirmed the MB overheat and incorrect voltages.

I've tried a new PSU in case that was faulty - no change. I've reseated the CPU - no change. I've fitted a new CPU fan - no change. I've updated to the latest BIOS - no change. I've fitted known good but different RAM - no change.

This is NOT a CPU overheat (that's running well within limits) but an INDICATED Motherboard overheat. The MB is actually running cool and this was confirmed by a laser temp gun.

Has anyone here had this problem and found the solution?

Thanks.
 

mrbob_21

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Dec 10, 2009
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18,510
PS: The PC doesn't hang, shut down, run slowly or give any error codes to indicate a fault - just the fan running at full speed!