I have a macbook pro 13 inch, model a1278 I plug in the ac adapter and the little light on it flickers and is very dim. I have tried removing and replacing the battery, and replacing the magsafe adapter with a known working one. I also have several chargers that work on my other macbook. So it is not the charger, it is not the battery, and it is not the magsafe. I will continue fiddling with it to try and make it work, but does anyone have any idea what it might be? Open to suggestions, aside from replacing the motherboard..