Chosen Solution
So this is pretty weird. The yuio keys of my Macbook Pro non-retina mid2012 keyboard sometimes become un-reactive. I found a way to reactivate them., which sometimes works, sometimes not… If I press t and y repeatedly for 10-30 times the keys will work for a while. I have seen several discussion threads with similar issues and I wonder if there is some cure, as it does not seem to be entirely hardware-related… However, in Bootcamp or in the filevault pre-boot login screen I get the same issue. I tried cleaning the logic board connector cable. I cannot remember spilling any liquid into the Mac. Thanks!
Sounds like a keyboard issue. If there has been a small amount of liquid on the keyboard, it can cause issues like this (sometimes some keys not working, sometimes working on their own, etc). Order a new keyboard, and plug it in to see if it has the same issue. Keyboards cost about £15-£20, so it is not very expensive and it is not a difficult repair to do.
Did you get any succes?
