you need to clean the playfield before play. mine was covered in something, you could see it if you looked side on. If you just cleaned the balls and threw them in & played, they'd pick up whatever is on the playfield and that could possibly scratch it.
Also the protectors stick up a bit, possibly catching the ball and nicking it. I'm possibly going to swap mine for cliffys but in the mean time, try reseating them.
Also the protectors stick up a bit, possibly catching the ball and nicking it. I'm possibly going to swap mine for cliffys but in the mean time, try reseating them.