I havce over 15 of these units and they're great...when they work. Recently I've had the following problem:
I'll have a dmx signal of 0 to all channels, power switch turned off on the unit and 1 or 2 channels stay ON. The green LED is off and the fuse it fine. When i take out the fuse the light goes off or if i unplug the unit, but no other way controls these freak channels. I currently have about 6 channels like this. They just stay on, again nothing effects these channels, not even the mode from dmx to pre-programmed moves. PLEASE HELP, I also have some of the same models with american DJ logo on it that do this as well!

The dimmer pack may be bad.
This is something I have not heard of with these dimmers, but you may want to call service department 1st and see what they say.
But you may need to send them in for service.

Best regards,