Hello, I just replaced my 2.2Ghz MacBook logic board with a 2.4Ghz 661-4709. I noticed that the fan is not coming on. Is this a compatibility issue? I tried a used 2.4Ghz board and the fan worked fine however the computer would not boot. I returned the board and purchased a new board and now the fan will not come on. The computer boots right up and everything (that I have tested) works fine. Everything except the fan. All the connections appear to be the same??? Any suggestions?