That same thing happened to my ZX 600 Concertcrap, too! The sub still works on "A channel", which is the 5 speaker surround sound in the main living area. I was under warranty when this happened, only it was the same day that I brought my camper home for the first time, BRAND NEW!!! They replaced the unit under warranty, and I haven't had any more problems, thank the Lord!!!
/SIGPIC]'08 V-lite Flagstaff 30WRLS
'06 Ram 1500 QC hemi
Reese dual cam sway control,
K&N series 77 intake, Hellwig helper spgs. LT tires,
Flowmaster "true duals", 380 h.p., Bilstein shocks