Thanks Graeme. Much apreciated. I read a few things about the mica washers not being as effective at getting the heat into the sink, hence the idea of just having the thermal compound. But you are right i will not start messing with things like the grounding in a system that i already dont trust lol. Thanks for the info on testing the wires, im pretty good with mechanical things but electronics baffles me at the moment.

Hi Robin, thanks for the input. You know now that you say it i dont know why this didnt occur to me that this looked like a previous repair. But it does look like a soldered over track and the solder gas blown, but again i guess its back to what caused the first failure.

Anyway i will report back what happens