Chosen Solution
no light on the adapter. battery is flat. have tried to disconnect the battery, reset left shift, command, option, start button 5 sec, different power adapter, what else can be done with a dead computer?? on thing interesting. if I plug an adapter on a computer that works, green light on. i remove this adapter and put it on the dead computer, the light comes on for about a minute then dims out. is there a way to follow the current to see where is the faulty part? thanks for your help. Update (11/22/2015) Yes when I press the button, only one light or all lights blink. This happens only if the adapter is plugged. If not there is no light at all. but my problem is that there is no light at all on the adapter, so I cannot start the computer. Is there a way to troubleshoot this situation? If the battery is dead, could that make that the adapter is not lighting and the computer not powering? thanks for your help? serge
Press your battery test button, it you get nothing or just one light it may be dead. UPDATE 11/24/15 SOUNDS LIKE YOU ARE NOT GETTING POWER FROM THE MAG-SAFE ADAPTER. Use a multimeter to test the out put pins, On the right of this wiki is the pin out: https://en.wikipedia.org/wiki/MagSafe
