Finally figured this one out.   I had described in previous posts that I felt the PX-350 keyboard was way too "clacky" and tough to play, as the key action was pretty punishing on the downstroke. I've also read similar from PX5s posts and this might solve your problems too.   I thought adding additional felt under the front part of the keys would solve that problem as there is a plastic tab that rests on a thin layer of felt under that part. This didn't work so I "went in" again. Here are pics