So I recently got this PowerBook G4 15" laptop which I am using at the moment. The battery is dead, it won't take charge. However, Mac OS X system info and Coconut Battery both display that the maximum charge which the battery can hold is around 2800 mah, meaning that the battery should not be dead. Then again I know that if battery depletes completely it will die no matter how many times it has been charged. The charging led is mostly green but sometimes switches to yellow for a brief moment and there has been time when Mac OS X said that the battery is charging but that didn't last long. I now had the chance to test three different 65W chargers which all worked fine with my "old" 12" PowerBook, I could power up the machine with or without battery. Guess what, this 15" PowerBook will not accept any of them. The only charger which is able to power up the machine is the original one. One very important thing which leads me to believe there might be something wrong is that even with the original charger there is relatively loud electric noise when the charger is attached and the machine is off, the noise stops immediately when the machine is powered on. The noise is not like there would be sparks or anything, I maybe cannot explain it, but it is like interference you could hear when radio signal is not optimal. So, what Macrumors thinks, bad DC IN board? How can three chargers all die around the same time? I have already ordered new battery which probably will answer this question, but it takes time for it arrive. I have tried all the resets but because of that electric noise, I don't think this has anything to do with PRAM etc. EDIT: Damn, just browsed iFixit.com and discovered that swapping is not as easy as with iBooks, I still think I can do it however.