Lionel A/F Gray UP Challenger 6-48084 no longer responds to Legacy commands and only runs in forward

An actual product number is always useful. From your description I'm guessing it's the Lionel 6-48084 Union Pacific LEGACY 4-6-6-4 Challenger #3977, right?

From the problem description, it sounds like a motor driver failure.  First step would be to reprogram the locomotive since this is using a back-EMF motor driver, when they lose their configuration, the symptoms are they take off at full speed, sound familiar?

Since it also fails to reverse, have you tried to mechanically move it with the motors backwards to see if anything is binding in reverse?  If not, you can proceed to the next step and start looking for electronic failures.

Thank you.  It is product number 6-48084.  The soft Reset key and default reprogramming procedure on page 17 of the Owners Manual do not make any difference.  Is that what you were referring to by reprogramming?  The motors move freely by hand in forward and reverse directions.  

A dumb question, do you still get sound?  Can you control the sound and/or turn the lights on/off?

My top suspect if mechanical issues aren't causing the problem is this part.

If I were looking at it, I'd probably pop it onto my test rig and see if it's alive.  I keep one of those in stock.

Here's a bit more information. With the tender on the engine all Legacy sound commands from the Cab2 work fine. You can also make the tender's reverse light come on and go off. You can even turn smoke on/off using the Cab2 while it is running. The problems are 1) the Cab2 does not control speed, you have to control its speed using the transformer, and 2) it only runs in forward.

Same answer as before.  Top suspect is the DCDE, followed by the R4LC.

gunrunnerjohn posted:

Same answer as before.  Top suspect is the DCDE, followed by the R4LC.

are there any common components on these boards that are prone to failure that can be changed by the end user?

Well, offhand it sounds like the board has multiple failures.  A shorted reverse driver would explain it drawing excessive current in reverse.  The fact that it takes off in forward suggests it's not reading the back-EMF from the motor.

You did take note of what I said about reprogramming, right?  That would have been the very first thing I tried.  If it has lost this programming, it will take off like a rocket.  From the manual for your locomotive...

Yes.  Thanks.  Reprogramming was one of the first things I tried -- please refer to my first post - "The soft Reset key and default reprogramming procedure on page 17 of the Owners Manual do not make any difference."  Given that it responds to other Legacy commands except throttle and reverse, does it sound like the problem lies in the DCDE board?  Any suggestions on what to do about that?  I wish there was a way I could test it and/or likely suspect components. 

Well, if you have another similar locomotive, you could swap the R4LC to eliminate that as a possibility.  After that, I think I'd be inclined to order the part.  I can test them, but I'm set up to do so.

Thanks GunRunnerJohn.  Let me think this over and get back to you on what I decide to do and discover in the process.  Thanks again for your insights, expertise, and suggestions.  

Sgaugian posted:

I would appreciate your help with a Legacy S-gauge Lionel American Flyer Gray UP Challenger that will no longer respond to Legacy commands and only runs in forward whether under Legacy or run in conventional mode with a transformer. What do you think might be wrong with it? Below is some more information about the way it performs.

In Legacy mode: When you power up the tracks to 16.5-18.0 VAC the headlight comes on as it should and the engine does not move. When you enter its ENG # (#77 in this case) on the Cab2 and move the red throttle control knob one speed step or more, or press any of the standard speed buttons including Roll, the engine takes off at a ferocious rate of speed. If you apply less power to the tracks (e.g. 5-8VAC) and follow this procedure the engine takes off less quickly and you can control its speed by varying the voltage to the tracks as if it were being run in conventional mode. When you press the direction button, the engine stops, but when you try to reverse it, the transformer humming pulses as if it is getting met with resistance and the engine fails to move.  It only runs in forward.  The soft Reset key and default reprogramming procedure on page 17 of the Owners Manual do not make any difference. The engine also performs this way when run with a TMCC Command Base and Cab1 instead of Legacy. It also runs this way whether the boiler shell is on the chassis or off the chassis and the chassis is run by itself.

In Conventional mode: The engine runs in forward and its speed can be controlled by how much power you apply to the tracks with the transformer. However, the engine will not run in reverse, only in forward.  When you toggle power to get into reverse the transformer humming pulses and the engine does not move. The smoke unit works and can be turned off and on with the slide switch. It also runs this way whether the boiler shell is on the chassis or off the chassis and the chassis is run by itself.

Thanks in advance for your time, attention, and recommendations on what might be wrong and what I should try to do to regain full Legacy operation of this engine.

S Gaugian,

   Early on after the release of the Challengers there was a response of the engine taking off at a high speed and the cab2 losing control of the engine. Depending on the direction which was affected it was suggested to check the engines antennas because they might be shorting against the body shell and causing the signal to be interrupted by shorting.

My question is what happened before your engine started acting erratic? Did it ever fall off the track on tis side? Was it ever dropped or do you pick it up by accidentally pushing on the hand rails. The antennas have rubber bushings where they  go through the shell and the wiring attach the antenna at the end. Now if they have been disturbed those wires can short out on the engine shell and cause many disrupted signals to your electric components within your engine also can cause damage to those same components. Carefully inspect those attachments and the rubber grommets so the antennas are fully insulated from the shell.

I only can hope this is your problem and no electronics have been damaged.

Don 

Don, Thanks for your reply.  As far as I can see there are no dents or damage to the external handrail antenna or internally to the wiring for them.  But the suggestion that it might be antenna/signal shortcomings is a good one and I've seen that be the issue before, especially with TMCC/Legacy conversions I've done prior to inserting the antenna lead wire(s).  However, one thing to consider in the case of this Challenger is that it responds to lighting commands (headlight on/off, reverse light in tender on/off), sound commands (Cab2 buttons and bell/whistle slide), and the rear coupler activation command.  Basically it responds dependably to everything Legacy, but throttle control and actually running in reverse.  

Anything's possible, but I'm thinking there's a fairly low probability that this set of symptoms is a signal issue.

Sgaugian posted:

Don, Thanks for your reply.  As far as I can see there are no dents or damage to the external handrail antenna or internally to the wiring for them.  But the suggestion that it might be antenna/signal shortcomings is a good one and I've seen that be the issue before, especially with TMCC/Legacy conversions I've done prior to inserting the antenna lead wire(s).  However, one thing to consider in the case of this Challenger is that it responds to lighting commands (headlight on/off, reverse light in tender on/off), sound commands (Cab2 buttons and bell/whistle slide), and the rear coupler activation command.  Basically it responds dependably to everything Legacy, but throttle control and actually running in reverse.    

   I this you would go to Carl Tuveson's Web page for on there he has a break down and his observation of the Lionel FEF Legacy Challenger and some possible problems. He can also help you find out just what the problem is or you might send you engine to him for repair. 

Link: Carl,s S Gauge Empire can be found by typing this into your browser

Don