Thankyou for your reply.
I have tried reseating the transceiver board. There is no difference if I am tethered to the remote or not .
I also tried removing the transceiver to see what would happen. With the remote tethered there was no change. Without the tether there is no response with the transceiver removed, as expected.
It seems like the transceiver is working, otherwise nothing would happen at all. Could there be some other component on the main board that is faulty?
I am not sure if this helps, but the whistle, bell respond better that the speed wheel. With the speed wheel I have to wait about 5 seconds before advancing to the next speed or nothing else responds on the remote.
The bell and whistle take about a 1/2 second most of the time. Again, with my new TIU everything works.