I had the same issue for months. The only way I was able to get the outputs to work was to follow these steps
1. Disconnect the USB cable from the TI
2. Disconnect the power cable from the TI
3. Disconnect the power cable from the power outlet
4. Reconnect the power cable to the TI
5. Reconnect the power cable to the power outlet
6. Reconnect the USB cable to the TI
7. Press and hold the ARP EDIT button for a few seconds (I usually do it for at least 10) and then let go