Hey there, I have an older MacBook Pro. The problem at first was, that it couldn't be charged by one specific charger, it only sustained the Mac's power and I used it as such. I charged the Mac by a charger I borrowed once in a while when needed. One day I let the Mac discharge to a point where it didn't want to turn on. Even the charger that worked previously wouldn't charge the battery. I thought the battery is dead, but it doesn't behave so. I have no option of trying the battery in another MacBook. When I turn the computer on without battery and insert it later, it is not recognized. But this is why I'm posting this thread in the first place. When I try and insert the battery really slowly, it starts blinking like it's charging for a long while, then stops. Here's a video, so you can see what I mean. http://youtu.be/TQEG_P2LmAs Have you ever seen anything like this behavior? Is it a sign of a broken left I/O board?