Q: keyboard cleaned, now not working, neither is external keyboard

I cleaned my keyboard on my MacBook Pro and now the "a" key doesn't work, nor do the numbers 1-9, and (get this) - the "h" key acts like "backspace".

Furthermore, an external wireless keyboard that uses a small receiver in the USB port doesn't work either, with the exact same problems as listed above.

So, it's not the keyboard then, I presume. It must be something else. But what?