I honestly don't know - it's such a bizarre problem.No luck with the power thing. Going to install Windows and flash bios this afternoon. Reckon it's worth flashing the GPU BIOS too if it's still dead or is this more likely to be a monitor thing?
The motherboard BIOS flash is definitely a worthy step as it may improve PCIE compatibility along with the memory - but still doesn't explain why it would work with a TV and not a monitor.
I too would consider flashing the GPU BIOS - makes sense - but again still confused with why this would stop it working with a monitor which worked quite happily within another PC before?
Actually, is the monitor a new addition too?