This sounds like an antenna problem. There are a few common problems that cause loss of FM and loss of both AM and FM, but loss of just AM is not something I've ever run into inside the radios on a regular basis.
Start by removing the radio while it's turned on and playing. If it improves while moving it around, look at the antenna connector to be sure it's pushed in all the way.
Friday, January 28th, 2011 AT 5:57 AM