Original post by: Darcy Patko ,
Most times when I come across this it is a buildup of dirt and oils in the mesh covering the ear speaker on the front panel. Start by [guide|31665|removing the earspeaker.] Once you have it exposed use a q-tip with isopropyl alcohol to moisten the buildup in the mesh. Then use a can of compressed air and the sharp tip of the spudging tool to scrape and blow away any buildup. You can hold the panel up to the light to see your progress. It may take a few soakings and shots of compressed air to free all of the buildup.