Answer to "MacBook Air not charging, not turning on"Hi Christian, I'd definitely check the I/O board first. It looks like the power from the charger isn't reaching the MacBook. Check the I/O board cable. If that doesn't help, I'd also check the battery. It's pretty unlikely though, because the MacBook should run off external power if a charger is connected, no matter if a battery is available or not. But you never know.