I think there are a couple 10uf 16v caps in the AEKII that can go bad causing oddities.

Pretty much the AEKII is my favorite vintage keyboard.

the IIgs keyboard is my second favorite.

My Favorite modern keyboard is apple aluminum keyboard /w keypad. they are rugged as hell, and i like the keys.

Mine at work gets nasty… I mist it with windex and wipe it clean.. and its just like new after.