Hi, I have a mid 2010 13inch MBP. The battery went kaput earlier this year so it has been entirely reliant on mains power. A few weeks ago however it started to shut down randomly even when plugged in. And just now I went to turn it on, with the power cable in and the indicator light on green, and it won't respond at all. Is there any point buying a new battery or is it completely dead? Is there anything I can do to try to figure out exactly what's wrong? Thanks EDIT: actually after holding down the power button for a while it has now come on with the fan at full blast. Is there any kind of diagnosis I can run to try to pinpoint the problem?