Main Causes & Solution

A. Something touching the strings

  Cracked bridge : recap bridge or repair with epoxy.

  Loose bridge pins : loosen strings, remove bridge pins with vise
grip, dip pins in epoxy and reinstall pins to bridge, let dry.

  No side bearing : re-seat strings to the bridge with brass rod and
bend pins to 15 degree angle side bearing, or plug and redrill pin
holes reinstall bridge pins.

  Insufficient down bearing : repair or replace sound board and or
bridges or place veneer on top of bridge; lower plate.

  Bridge pins too short : install new bridge pins

B. No string tension

  Broken plate (cast iron frame) : we can only hope this is not the
problem.

Bill Maguire