Yamaha clavinova clp 560 loud keys when played softly

I bought a clp 560 and when playing some of the keys are louder than the others when played , i have been told its the felts but dont know what or how many it has and dont want to open the back of it up and not be able to play it , without renewing the items listed.
Does anyone know or have a parts diagram they could post

Many thanks

If what you bought really is a CLP-560 - that is very old - released 1990.

you need to replace the rubber contact strip - part # is vc799200 - you get it from here: