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Hello, I have a Macbook Pro A1278 2012 No led light at all on the MagSafe. No battery charging. What can I do? I tried a NEW battery and it didn’t work and I tried a NEW DC-IN and it didnt work also. Thanks.
You seem to have a lot of different Macs. First try disconnecting the battery from the logic board. Also the mag-safe. Press and hold the power on button for 5 seconds. Reconnect and give it a try. A history of the machine might help. Let us know if your get anything, lights sounds, etc.
Important to know the history of the machine, any drops, spills etc. If you don’t know the history you will need a schematic, board view and a multimeter and you will want to start test the power rails to see what is and is not present. Once you have narrowed done what power rail is missing you can then begin to diagnose the issue. I have attached the page you need to get started testing start with PPBUS_G3H
