So went away on the 29th. Tried to boot the pc today and it's absolutely dead. I had the power switched off at the socket though everything was plugged in.
There's absolutely zero lights or sounds. I've switched over the plugs from the monitor to the pc and both cables are working fine. I've held the power button for 20 seconds, I've taken the battery out of the motherboard for 10 minutes and tried again. It's completely dead.