My friend has a 2014 MacBook Air 13" i7 that he had to get the keyboard and track-pad replaced on after a coffee spill. The shop replaced the keyboard after two months of sitting at their place, and it does work now... but only kind of. None of the function keys do what they're supposed to normally, such as adjust keyboard and display brightness, sound, etc. I looked to ensure the setting "Use all F1, F2, etc. keys as standard function keys" wasn't checked, which it wasn't. Used a keyboard map tracker and found that all function keys are recognized, except F11, which for some reason pulls up Mission Control, and the Fn key seems to do nothing to their mapping (although it still works to wake from sleep). Erased everything and did a clean install of El Capitan -> Sierra. Even tried resetting the SMC, all to no avail. I'm really stumped with this one. What could be wrong?