Hi all - I've made a bit of a boo boo i think. I'm fairly computer literate, I've taken a good few PC's and Mac to bits and upgraded various parts with no problem. This is what I've done : Removed 1.5GHz core solo and replaced with 1.83 T2400 Core Duo. Installed new Superdrive (replaced combo) Rebuilt and switched on. Now only the white light comes on, no apple chime. Pressed the reset button on the logic board: no chime. Tried reset PMU (http://support.apple.com/kb/HT2183?viewlocale=en_US) the realised that it's an intel board and reset the SMC : (http://support.apple.com/kb/HT1543?viewlocale=en_US) (After doing the hold power switch and plug in power lead- the fans come on and stay on full) Reinstalled all the original gear (optical drive and CPU). Still stuck at the bit just before the apple chime. Even tried removing the RAM to get a different chime out of it. Nothing. Even tried swapping out the hard drive. I'm thinking that it might me a new Logic Board. Trouble is that all I can find is $500 options. That'd be as much a new mini. Anyone got any ideas?