Apple Keyboard with numeric keypad problems I have a very strange issue with my wired Apple Keyboard with numeric keypad. When I try to type the large letter Q by pressing the left Shift key, it doesn't work. However, when I use the right Shift key, it works. The left Shift key works with most letters, but not all. The option key works in some shortcuts and in others it doesn't. The next (F9) and the mute (F10) button don't work. Typing some diacritics works, but not in all cases. It's seems totally random.

First I thought something's badly configured in macOS (newest Sierra release), but the keyboard has these same issues with every other computer. How is it possible, that some key combinations work and others don't? I do understand that keys stop working, but key combinations?

All this happened after a routine cleaning of the keyboard with a moist cloth. It happened to me once, a few months ago. One button stopped working temporarily, but a month later it started working again.

Is it possible to fix this somehow or do I have to buy a new keyboard now (the warranty is up)?
Sounds like you got water inside.   

It might be cleanable, professionally; or some of the tracks may be corroded.
Your call - get a quote for a fix, or just get a new one &amp; don't get it wet again :/

See this answer to a not really related question for a 'cruel but fair' analysis of how bad water is for electronics.