I spent most of the afternoon unsuccessfully trying to get the WK2 to play GM sequences on all the channels it's supposed to. I've tried many different things but nothing seems to work.

I'm not sure why when I try and play a MIDI sequence from the computer, either from Band-in-a-Box or from a regular sequencer such as Logic Audio through the WK2, it only plays back on channels 2,3 and 10.

Anything on 4, 5, 6, 7 or 8 will not play, although there is sequenced material on those tracks. The WK2 should act like any other GM module and play all tracks. The unit is in GM mode

As an experiment, I took the track that was being sent to channel 7 that I couldn't hear and routed it to channel 3 and it worked fine. Conversely, if I took the material from channel 3 and routed it to 7, I no longer heard it.

Also, If I mute all the channels except 7, I notice that the MIDI light still flashes on the WK2, which means it's receiving MIDI information on channel 7. What it's not doing is turning the MIDI information on channels 4 through 8 out through the audio outputs or the headphone out. That's the only thing I can figure.

If I send the same sequenced material through any other GM module, everything works fine, with all channels playing all the material fine.

Is it possible it's a defective unit?

Thanks for your help.