Update... it died again

This time it ran for 2d 3h 9m (previous run was 2d 13h 16m). I checked over the mother board but couldn't see anything wrong, and all the chips are soldered so no dodgy IC sockets to wiggle.
It's probably a cracked track or dry joint that goes open circuit when things get cold. 1st death 03h01, 2nd death 01h55 in a well insulated attic. I know the PSU and CPU get nice and warm, but bits of the motherboard (especially at the front where the fresh air is drawn in) track the ambient temperature.
Oh well, on with the PIC microcontroller data logging project then

Cheers, Mike.