Teacher's piano problem

[A440A@aol.com]

        Perhaps it would be a good idea to put in another hammer on a spare
shank, and see if the problem can be found in the hammer or the sounding
structure.

Here is my guess,(don't ya just love it, trying to voice by wire?)

I think that there is hardness in the felt of the hammer, and a chopstick
needle approach just might find it.

Ed Foote