A:AnswerI had the same problem with my Yamaha Aventage 830 and my sub. You're going to need to reset the receiver which you can find how to do online and then run the YPAO speaker set up program again. That should take care of the problem if you don't have a faulty subwoofer output on the receiver. You may need to do it more than once as mine didn't begin working again until the third try.
