Right............ I have been given a couple of towers to look at from a friend of the family, as i thought i might have been able to repair them. The problems is and this is with both towers, that when i connect all the wires to the towers and goto switch them on they both are already powering up, but nothing comes up on screen, and all the hardware (gfx card, fans, hard drive,usb slots, memory, cpu, fan, cd drive, floppy drive) seems to be powering up fine and working ok as i have tested them in other machines. When i try different power supplies in both of them neither of them power at all. Am i right in thinking that it is a motherboard problem, or is there something else which might be causing the problem at all?