Sudden poor FM reception in '95 Z28 factory BOSE CD player???

The factory BOSE CD player in my '95 Z28 has suddenly lost good FM reception. All FM stations used to come in very clear, but now they barely come in and have scratchy static. I checked the coax line at the antenna and the antenna itself - all looks good. I pulled out the head unit to make sure the antenna cable was still plugged in - no issues there. This leads me to a faulty head unit regarding the poor FM reception or possibly a break in the antenna cable somewhere between the head unit and the rear antenna? Everything else on the head unit works fine and sound is crystal clear with a CD. Thanks for any ideas!

Jeff