The disassembly and reassembly does not scare me, as I have been through worse many times before. Removing the ram and using the onboard only does no difference. It is possible to power the motherboard outside the case on this machine (connect only vital parts and the LCD) so there is no need to assemble everything each time I want to try stuff.

My main problem is that I have no parts, therefore I am stuck at square one. I still believe this is a DC board issue, as faulty voltages wil cause issues such as the ones I have mentioned. I will get myself a new DC board and then we will see if it will solve the issue.