These units have what is known as a Rotary Encoder. They're just like the volume controls on audio equipment, now a days. You can turn it all the way, and it never stops. The pulses from these encoders, are routed to the microprocessor(computer inside your unit). The encoder may be bad, or the microprocessor itself. If you'd like to enquire about repairing your unit, please contact me directly from my website at audioserviceclinic.com. Thank you.
Answers & Comments
I had the same thing happen to me on my korg triton and had to replace the encoder on mine if you are good at soldering.
https://www.fullcompass.com/prod/527110-tascam-e0040080-2488-mkii-rotary-data-encoder-wheel
These units have what is known as a Rotary Encoder. They're just like the volume controls on audio equipment, now a days. You can turn it all the way, and it never stops. The pulses from these encoders, are routed to the microprocessor(computer inside your unit). The encoder may be bad, or the microprocessor itself. If you'd like to enquire about repairing your unit, please contact me directly from my website at audioserviceclinic.com. Thank you.