Transporter question

Hi - have a Transporter (black) in mint condition I recently picked up. No manual though leading to this question.

This one does not have the dial/knob in the middle, if just has a flat, round things where the knob would be. Is this supposed to be touch sensitive? On mine it doesn't do anything so for most functions I have to use the remote. Just curious if that has failed and, if so, if there are any known fixes.

Thanks