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Hello, I have a MacBook Pro from 2012, A1398. The following keys are no longer working. left shiftleft ctrlleft altleft cmdright shiftF1 - F9 On an external keyboard these keys are working. SMC reset is not possible as the according keys do not work. Any idea except exchanging the keyboard? Thank you Update (11/21/2020)
Thank you Dan. Actually I replaced the battery yesterday and the problem has started. Could you please describe where the battery should touch the keyboard cable. For me it seems separated (I have not removed more then the battery so far). I tried to search for a cabling diagram for the keyboard to see the connections with all the keys which are not working. I removed the keyboard connector and cleaned it (further if I shutdown, most of the time I have to remove the power cable and the battery cable, press the power button and replug the power cable, then the system boots, otherwise not. Afterward I also re-connect the battery cable. For this additional problem I would like do the SCM reset). BTW - For upper case I currently work with caps lock, or using the keyboard viewer tool - there I also see clearly which keys are working. This beside the workaround with an external keyboard.
At this point you’ll need to check a few things. The first is strangely the battery! As the battery ages it off gases and like a ballon it expands with limited places to go. Often it presses against the keyboard and the keyboard cable which can damage it. Install this gem of an app! CoconutBattery take a snapshot of the apps main window and post it here for us to see Adding images to an existing question The other issue is liquid damage on the logic board at the keyboard connector area. You’ll need to pop the bottom cover off to inspect that as well as double check the battery if its blistered up MacBook Pro 15" Retina Display Mid 2012 Lower Case Replacement Sadly, that still doesn’t deal with the elephant in the room the keyboard its self could be damaged either liquid or due to a failed battery. That gets into replacing the keyboard or upper case following this guide MacBook Pro 15" Retina Display Mid 2012 Upper Case Assembly Replacement for either and then if you are up to it undoing the 50+ screws to pull the keyboard out: MacBook Pro 15" Retina (Mid 2012-Mid 2015) KeyboardMacBook Pro 15" Retina (Mid 2012-Early 2013) Upper Case Assembly
