HI I have a friend whose G4 Macbook logicboard failed. my understanding it will be about $450 to replace. I am trying to help him decide if it is worth replacing. If he replaces this part, will there be other repairs ahead (such as screen failure). I have had an G3 Ibook dual USB 500mz with no problems for 7 years. But I have read G4 macbooks may have troubles. If he chooses not to repair it, what value is any on EBay? thanks.