Nothing other than the CPU was replaced.
No flashing lights.
I am not aware of any bios updates. The customer stated that the unit was working, started flaking out. He powered it down and it would not power back up.
My thoughts were along the line of a clogged cooling system and a burnt CPU. When I got into the unit it was actually very clean. So no sign of or smell related to cold solder joints or circuit damage. I went ahead and replaced the CPU just in case.