Salut ! 
Did you put trigs on the Thru track ?
So it can be an audio problem and/or a midi one. In order to simplify tests, and solve things 1 by 1, I’d plug a TD3 to OT (Input CD), set a midi track to play the TD3. Play and monitor the sound with DIR CD (MIXER PAGE), or directly on the TD3 with headphones.
If you don’t get sound, change the midi channel on OT or TD3, check your midi cable with a working config.
Topic francophone :
[FR] Le Bistrot Francophone Intersidéral