Ran in to a similar problem to this years ago. It turned out to be the car top processor box. The cooling fans had stopped working in it and there was a larger bundle of wires that were sitting directly on top of the processor. This was an early Epoch II, by the way.
Epoch II was eventually transitioned to the Miconic A name and included a whole host of progressive upgrades, including ditching the car top processor for HVM boards, etc...
Good luck.
