PowerEdge 2400 CPU overheating

Hi,

I have an old 2400 tower server with 2 CPU's in which is being used for a basic email system. During normal operation the temperature of one of the CPU's fluctuates up very near to the critical temp as viewed in OpenManage at around 70 degrees, whilst the other CPU remains fine. All fans appear to be working OK although at a higher than normal speed in order to try and cool the overheating CPU.

I am wondering if this is likely to be a CPU fault or a temperature sensor fault, do the CPU's have a temperature sensor built in?

I think our options are :-

1. Replace the CPU.

2. Remove the overheating CPU and replace with a blanking module leaving one CPU

3. Replace the motherboard (although using onboard SCSI RAID)

Any ideas what the most likely cause and best resolution is? Thanks in advance.