My MacBook "e" key stopped working, Didn't work in recovery drive either + Worked on external keyboard so deemed it a hardware issue. Ordered keyboard replacement,switched it , booted and still no "e" button functionality?! (Also sound not working anymore after the replacement + screen flashes repeatedly for about a minute after initial boot then goes back to normal, any ideas why?) I'm stumped at this point can it be an issue with the motherboard? Also , strangely, after booting into recovery and testing it in terminal - right away "e" one after another with out me doing anything and wouldn't stop until I clicked another key. At which point "e" would not work when pressed.? please help thank you!