do you see midi activity on the midi monitor in the transport? Are you selecting the arrange page track with the instrument? Do you have an audio connection for the computer? Can you take a pre-exisiting midi sequence (or make on in the matrix editor using the pencil tool) and then play it back on the instrument?
It seems that I have a problem which is been
welknown for Logic, I have signal from my ext. keyboard but no sound from the internal
instruments.