Maybe a batch of dodgy caps, along with the dodgy Darlingtons?!

100v 105C caps are not exactly expensive or physically large, so a bit of
a
no brainer for bullet proofing this application.




Gareth.


no room for that size, unless put on track side of the pcb . As it happens
space there and as the temp sensing TO220 s and fan air flow/temp sensor
that side already I will solder replacements on that side I think