lionel lionmaster TMCC big boy wont move forward

I presume this is the 6-38075 Union Pacific TMCC LionMaster 4-8-8-4 Big Boy #4024, right?  I really helps to give us the actual Lionel product number right up front.

Since it runs in reverse, that eliminates some issues.  When you try to go forward, it doesn't more at all, right?  When you say power shuts down, is that the transformer breaker tripping?  What transformer are you using?

My top suspect is the Odyssey motor driver board.  It's fairly common to have a shorted FET on those and cause this exact symptom.

Yes, you have the correct engine, the 6-38075.   The power shuts down to the track.  I use an old ZW transformer but I also have a Legacy Power master on the track for extra protection.   Whether its the power master or transformer tripping, I'm not sure.   I've actually turned off the Odyssey switch to see if it made a difference but I got the same results.  If its the Odyssey driver board, would it still do this?  Thanks

The other top suspect sadly on these Lionmaster engines are the gears themselves. They tend to go into self destruct mode, and chew themselves to pieces…..and sadly moreover, with no parts available to fix them…..

Pat

@Ritch posted:

Yes, you have the correct engine, the 6-38075.   The power shuts down to the track.  I use an old ZW transformer but I also have a Legacy Power master on the track for extra protection.   Whether its the power master or transformer tripping, I'm not sure.   I've actually turned off the Odyssey switch to see if it made a difference but I got the same results.  If its the Odyssey driver board, would it still do this?  Thanks

Yes, turning off Odyssey doesn't change the fact that you need the motor driver output FET's.  My suspicion is one of those has shorted, and when you go into forward, the shorted FET and the forward drive fight it out and trip the breaker.  It could also be the control circuitry, but there's no way of knowing without checking the FET's for a short.

You can replace that board with the ERR Cruise Commander M, they should be available again this month.

Thanks so much for the information.  I greatly appreciate it.