Roland Compurhythm drum machine CR8000 with faulty or worn buttons.
Sounds a lot like the TR808, but a design fault makes these buttons useless after a while.
You will have to pull the plastic covers first, to reveal the spring and rubber dome under which we will drop a bit of conductive paint..
To pull the plastic part you need to push the sides using a screwdriver or two like on this video:
Youtuber The Imp Of The Perverse has made a few vids of his restoration-he used my method too, check them