Piano World Home Page Forums Our Most Popular Forums Piano Tuner-Technicians Forum Yamaha M500 CV rattle

It has a metal damper stop rail. When I play notes in the mid section, there's a rattle. When I apply a gentle pressure to the rail, it stops. I've tightened the screws holding it down. There doesn't appear to be any loose parts.

Here's a youtube link:

https://www.youtube.com/watch?v=l-2mx5wJf8A

Ok. Figured out a solution. Don't know why it worked, but, if you look in the video, way down inside the action, below my finger, is an adjustable support. It's just a screw with a rubber end that rests against the plate. There is a lock bolt that tightens up against the action rail.

I figured that perhaps pulling on the damper rest rail just seemed to stress the action rail in some way, and that's where the rattle was coming from. When listening closely, it seemed to radiate from the action rail or damper rest rail as a whole; if I moved left or right, the rattle seemed to follow me.

So I just loosened the lock nut, turned out the support screw a turn, and tightened the lock nut back up.

This does change the geometry a bit, but everything still worked well.