<HTML>Most likely a case of expanding action brackets.  Check the serial number, and if the piano was built between 1991 and 1995, don't put any more effort into changing regulation before calling Young Chang and discussing it with them.  It's a problem that they're familiar with, and they will send you replacement brackets and instructions for installing them.  Labor to do the job should be covered under warranty. I recently did a set, but I'm pretty sure that somebody had previously attempted to straighten out the regulation on the piano - which made the job more work than it should have been. Mary Bailey I went to a Youg Chang today,about 10 years old,for a tuning.I tuned it once about 3 <BLOCKQUOTE TYPE=CITE style="BORDER-LEFT: #0000ff 2px solid; MARGIN-LEFT: 5px; MARGIN-RIGHT: 0px; PADDING-LEFT: 5px">or 4 years ago.I got there and every hammer was blocking,I'm not talking about buzzing,but major blocking</BLOCKQUOTE> </HTML>