While riding using a usb thumb drive the sound goes out. Sometimes it quits all at once and today all quit but the right rear speaker. The usb drive is continues playing (the time counter continues and it even moves to the next song. The only way to get sound back is to turn the bike off and back on, sound returns immediately Am I looking at an amp going bad. Also when I bought the bike AM/FM didn't work and showed nothing on the display. Any thoughts.