TMCC Odyssey Motor Feedback question, 6-28540

You have a TAS EOB- Train America Studios - Engineer On Board and that is the optical tach(ometer) reader.

Manuals, instructions, and diagrams are found here https://ogrforum.com/...rials-andamp-manuals

Example diagram of what is likely the motherboard here https://ogrforum.com/...rboard%20Pinouts.pdf

TAS EOB install and documentation https://ogrforum.com/...20EOB%20Complete.pdf

I know of 3 common failures:

#1 the wires to the tach sensor board mounted on the motor break from the motor flexing as the truck turns between straight and curved sections of track.

#2 The tach sensor dies or is damaged- sometimes caused by the wires breaking open circuit and or shorting. I thought that @gunrunnerjohn had created a firmware solution for his chuff generator sensor to replace these? Example https://ogrforum.com/...3#113911143598516973

#3 in extreme cases, the processor chip on the motherboard dies- however given yours still responds to direction I think it's not that in your case.

Examples:

TAS EOB help topics https://ogrforum.com/...-tas-eob-help-needed

https://ogrforum.com/...41#80973530377497741

Well, I say you have a TAS EOB, but the picture you gave only showed mostly the sensor

- so I know you have some form TAS EOB, but it also could be the modular version to replace a DCDR or DCDS Odyssey and use the original Lionel motherboard. That was called TAS EOB drop in. This would be mounted with a heatsink probably at the other end of the motherboard?

https://ogrforum.com/...20Board%20Manual.pdf

EOB has built-in momentum, so starting slow and ramping up to a speed is the way it is supposed to work.

Again, after more reviewing in the picture, if it is a modular TAS EOB drop in board, and it has failed and the tach sensor doesn't fix the problem or say there is no problem- that's just "momentum". Then another route since TAS is no longer really around, could go with an ERR Cruise M and IMO that would be an upgrade and not require any tach sensor.

Note, 3rd Rail says they are out but ERR dealers might have stock?

http://www.3rdrail.com/err-3rdrail/

Like Bob said, EOB has a built in ramp to speed setting from a dead stop. There are 3 control modes you can access from the CAB-1. You have cruise off, 32 steps, and 128 steps. Most likely it’s in 128 step mode. If you hit the boost button from a dead stop it should roll at the first speed step. You can advance through the speed curve by tapping boost in 128 step mode.

Checking the tach/encoder is simply a matter of rotating the flywheel and seeing the LED light up for each stripe.

As with any cruise system, checking cruise function can be done by running at the lowest speed setting and holding onto the coupler. You should feel the engine pull harder if it’s in some type of cruise mode.

Thanks to all for the feedback and apologies for the slow response- I have been a "pseudo parent" since last Thursday (i.e., grandparent to older grandchildren).

I had read about TAS and EOB in the threads I found on the forum but that technology came up when I was a post war conventional runner and was a blind spot for me.  thanks for the details and these insights have helped a ton.

I plan to go through additional testing per the documentation provided and post results.  I don't want to waste everyone's time by missing something I should have seen.

Update, I completed some testing and as far as I can tell the led on the sensor board lights as the tape moves so that appears to be fine.  I also could not see anything that looked like a broken wire, leading from the sensor board.  I also did Norm's test and the loco did not feel like it was in the cruise mode- especially since it will not stay in the lowest cruise setting. It ramps up speed on its own without me touching it.

Here is an additional photo of the entire suite of boards and (although I am not the expert) @Vernon Barry I do not think I see an EOB drop in board?  I have not fooled with an ERR conversion but is that feasible based on this board structure.

Follow the wires of the sensor.

@Vernon Barry posted:

Follow the wires of the sensor.

Well, I will be blanked.....

As noted, assuming I can find an ERR cruise M, per these instructions, it appears it can be installed in this loco?

Yep, that's my advised route- upgrade to ERR Cruise M.