Could be some of short in the wiring, for instance, a malfunctioning power switch. Also if it's an old system the CMOS battery may be starting to go.
Originally Posted by kvmn82
may want to look at voltages or a lack of power, your problem reminds me of a computer running at the min range of its amperage. Could also be your bios panicking over a voltage mistake that isn't there
Originally Posted by Albatross1991
To simplify, the question is "What is corrupting my BIOS"?
In my opinion it is either a shaky power supply or RAM.