I use the Denon DN MC 6000 and lately the master volume on the controller has stopped working. The slides work fine. The master volume works sometimes and other times it doesn't for some reason. Right now it isn't working at all. Anyone using this controller have this happen to them or do you know why this is happening? It weird because sometimes it works and sometimes it doesn't. Everything else on it works fine. Just this one issue. Please help if you can. I use VDJ 7.