I bought a MacBook about 3 months ago and it has been going fine up until recently. Last week it started switching off as soon as I disconnected the power cable, and it won't switch on without it. Was just wondering if anyone knows how to fix this problem as it isn't very useful to me if I have to plug it in all the time. Like I said, it was working perfectly fine until last week, then one day it just decided not to work without the power cable. Any suggestions would be greatly appreciated.