The sound suddenly stopped working on my 2012 Forester radio last week- everything on the radio appears to be working perfectly fine- just no sound. Everything else in the car appears to be working fine, too. I was parked in my driveway and had the radio on- and then moved my drivers seat back and the sound suddenly just stopped. At first I thought it was the audio cable coming from my iPhone, but then realized there was no sound from the radio whatsoever. It's the original, basic radio that came in the car. I've never had issues with it before- does anyone have any clues what it could be? I was hoping it was something easy I could fix myself.