@RickO posted:Another possibility. I have experienced 2 TMCC remotes were the throttle knob was defective. One was bad out of the package. Assuming there are few if any "new" Cab 1 remotes, the risk of issues is always there.
Throttle response was all or nothing. Once the engine took off a full speed no amount of throttle turns would stop it. It was like the rehostat would lose its "zeroz' point.
If you had another TMCC loco to try, it might help with the process of elimination.
I just fixed a CAB1 remote with a bad throttle. The fix was stupidly simple. When someone had the remote apart (evidenced by the wrong screws being used to hold the remote together) the throttle red dial encoder circuit board got angled rather than being vertical in it's holder brackets that are in the front and back halves of the remote. This is turn also slightly bent the optical LED or receiving photodiode so even when the board was put back in position,the beam through the encoder wheel was slightly off. Slight pressure and bending and careful assembly and it's like new.
Again, Cab1 uses an optical encoder wheel- not a throttle pot. If one or both of the beams are out of alignment or damaged it cannot identify rotation. https://www.machinedesign.com/...atureencoder-signals
