May have to take you up on the battery offer, but it's a case of when, just been through a house move so I'm a bit strapped for cash at the moment.

Bit if a development, went to test the fan earlier today. Lifted the connector and it just fell apart, wires pulled out of the connector block completely. Fortunately managed to find the same style connector block on the microphone cable of one of my dead iMacs, swapped it with the broken one and it's as good as new, wouldn't even tell it had been repaired.

Also gave the processor connectors a clean with alcohol, refitted the processor to no avail, it still won't power up consistently. I'll reseat it again later and see how it goes.