Thanks for the additional detail info. In this case it is a non-articulated steam. A related question is the steam engine with the 5V board seemed to have just quit working. I think the engine was going really slow and may have quit moving (binding) and shut down. Now no longer works. The engine is on a test track by itself and no longer do I hear the click when it gets the watchdog signal. Other engines put on test track do fine so comfortable that TIU works fine.
Does this mean board is dead or could it be the small 5V regulator mounted to frame? This is a RK engine so don't want to spend much to fix.
