Technics sx pr53 digital piano with logic 8 - sound problem

I had managed to get the keyboard connected to logic, after reading your advice, it worked fine.
However, now there is no sound, you can see that the signal is there when I play the keyboard and look at the transport bar. I have the record button on the gm device track switched on. If I record the keyboard you can see the notes show up on the track, (therefore part of the connection still seems to be working) but there is no sound at all when I hit the keys or replay the track.
I went into AMS in utilities to check and it is still showing the technics info.

Any ideas on what I could be missing?
Thank you.