Hello, I have an iBook G4 12" that got knocked onto its open screen a few months ago. A day or so later, the Num Lock key and Volume keys started to switch functions and the result was the screen going blank. We bought another iBook that had a broken logic board and combined parts. Everything is all back together and setup but now the fan isn't going on and the screen is unresponsive. Does anybody now what the problem could be?