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Hi! I have a Mid-2012 MacBook Pro 13 inch which had a damaged connector cable between the hard drive and logic board. So I ordered the part from IFIXIT, as well as a battery, and installed the two new parts Now, after getting the two new parts installed and starting up my computer, the 1-8 (i.e. 1,2,3,4,5,6,7,8) keys are not working on my laptop. I have tried resetting SMC, resetting PRAM, checking mouse keys and updating macOS, but those keys still do not work. It is odd because the keys for 9, 0 along with all the other keys work just fine. I have also tried plugging in an external keyboard and even that works as well. What can I do? Thanks in Advance.
Ouch! You lost a keyboard row! This is what I would expect as the rows and columns of the keyboard are not aligned as you would think. With some exceptions the keys are arranged so the needed number of lines is less and can be encoded easily by the keyboard encoder. So the bottomline here is either one of the keys is jammed down or your system had a spill which corroded the given row line from the keyboard on down to the logic board connector or the ribbon cable or contact at the connector was damaged. I would inspect the keyboard ribbon and connector on the logic board. Do you see any damage or corrosion?
If not you’ll need to replace the keyboard. Here’s the easiest way to fix your system just swap out the upper case MacBook Pro 13" Unibody (Early 2011-Mid 2012) Upper Case getting the B or C stock which is the cheapest ($80 or 29) or you could just replace the keyboard MacBook Pro Unibody (A1278) Keyboard which is tedious as you have a ton of screws to take out and put back. In any case here’s the guide MacBook Pro 13" Unibody Mid 2012 Upper Case Replacement
