Hello, This is my first post on this site, so hopefully will get some good info from you guys. We have a clients 15" Macbook Pro Mid 2012 A1398 in with us for repair. Initially the Macbook would turn on intermittently, with times not turning on when pressing the power button. We would have to disconnect the battery and reconnect in order for it to turn on again. The Macbook was completely full of dust and clogged up, we suspected overheating may have caused this to happen. The client has come back now with the Macbook not turning on at all, disconnecting the battery doesn't work, SMC doesn't work, shorting the power pads on the logic board doesn't work and the weirdest thing is the MagSage charger turns orange as if it is charging the battery even when the battery connector has been disconnected. This is the first time I have seen this. Wondering if you guys can shed some light on it. It's either a logic board/GPU isse we think. Thanks in advance.