Hello, I have recently purchased a Power Mac G4 MDD Dual 1,42Ghz. All I wanted to do was swapping the CPU board with my MDD 2003 single 1,25Ghz. I turned the 1,42 on, everything seemed to work, so later on I swapped the CPUs. Now the 1,42 MDD with a swapped single 1,25Ghz CPU works just fine...