I just bought a MacBook 2006 model from eBay (1.83Ghz, 1GB RAM). Its a great laptop, but the only problem is that it only runs off the mains power. Before I go and buy new parts, I just wanted to know what the problem could be. It has the classic "black x" battery in the menu bar. The seller told me that the problem was not the actual battery so I just want to know what the problem could be. Please note - I have already tried reseting the SMU. Thanks in advance.