This morning the radio did not seem to work. I pushed the Audio button on the side of the MFD and screen showed "Audio Off". I pushed the audio power button (rectangular button above the volume control knob) and nothing changed. I pushed the same button many times, sometimes briefly, sometimes holding for a while, the MFD always showed "Audio Off". Could it be a bad button or a blown fuse? Where is the fuse? Thanks!
Update: Yesterday and this morning the button decided to work fine and I can turn the audio on and off without any problem. I wonder if the 12V battery was partially discharged (see this thread) and made the computer confused until some ignition on off cycles. The radio stations are all still in the computer memory.
If this should happen again, try hitting the face of the stereo with the palm of your hand, not too hard. The idea is to see whether you can temporarily clear an intermittent connection between the face panel and the rest of the stereo.