I am going to be taking the machine down which houses the mail spool and also debian and scientific7 virtual machines tonight to run some diagnostics.
The machine spontaneously booted again today. The thing that makes this so difficult to troubleshoot is that it is not generating errors in between reboots.
I am concerned that the problem with the BIOS the other day either resulted in damage by overheating components, or the motherboard may already be damaged which may have been the root cause of the BIOS losing it’s fan settings.
I am going to run some diagnostic software to try to see if there is some marginal hardware and also going to try to remove a Linux option that overwrites the processors firmware. This module caused problems on another of my machines so it may just be bad software, however, there are two identical machines in terms of hardware and only one is having problems.