My 12" iBook G4/1.33GHz only charges when turned off or in sleep mode. I originally suspected the battery and/or DC board, but after mentioning the flaw on a Craigslist post I got some feedback from a fellow Mac enthusiast, who believed the problem to be a bad power management chip. He told me of a group in Ohio that will replace the bad chips for $150-200, but since I'm not afraid to tear these computers apart, I was wondering if anyone here had advice (i.e. where is the chip located, and can I order it fairly cheap?).