Chosen Solution
Hello folks, Just replaced the battery for my 15” MacBook Pro (mid-2012). So far, the new battery is working as expected. However, some of the keyboard keys (Space, Delete, Cap lock, left arrow, down arrow) are not working! I tried the following: Reset SMCReset PRAMDisconnect and reconnect the keyboard cableChecked system settings None of these helped. Any suggestion? Please help! Thanks in advance Here is how the keyboard cable looks like:
I would inspect the keyboard cable and the connection to the logic board. Disconnect the battery and carefully slide out the ribbon cable from the socket use cotton swab (Q-Tip) with some reagent grade Isopropyl alcohol to wipe the contact surface, if it looks damaged you may need a new keyboard. Refer to Step 24 & 25 here: MacBook Pro 15" Retina Display Mid 2012 Logic Board Replacement
