I am trying to fix my friends PC. Apparently she didn't help keep the computer clean so all the dust built up inside caused the fan on the processor and the power unit to fail. In turn shutting down her machine. I put an ATX power supply on and bought a new fan for the CPU. I took the harddrive out and put it into my machine and the harddrive works, I could see her desktop. I put it back into her machine and it will not even power up. My question is.......Will the harddrive still power up if the processor isn't working?