Lionel 11116 844 FEF

The tach ring on the flywheel could be loose. Check it. Make sure it's tight. 

Thanks Marty,  Just checked and it is tight

Chrico-

The R4LC receiver is definitely in the locomotive, so I would look for either a single yellow or single gray wire coming from the locomotive's motherboard and going to the shell. Sometimes there is a quick disconnect attached to this wire, which is helpful when you need to separate the shell from the chassis.

If you see a loose wire that isn't connected to anything, most likely this is the antenna. If so there look for evidence of a broken solder joint somewhere on the inside of the shell; reattach the wire there and it should be back to normal.

-John

The handrails should have a pretty obvious connection at one end that goes to the board.  If it's not there, that's a problem.

I discovered that on this particular engine the connection to the handrails is inside the all weather cab.  After removing the two screws holding the cab on, it can be tilted enough to check the connection to the handrails.  I do not know if the connection is soldered or crimped on, but it feels solid. Tomorrow, I will do a continuity check from the connection on the handrails to the mother board.  The black wires from the handrails do go thru a multi wire disconnect 

Chris

Chrico:

I have this engine and it is fabulous, but I have had my share of problems with it.

1) with the shell off, go to every single circuit board and make sure it is seated properly and firmly to the receptacle.  Sometimes these boards do not seat all the way or come loose when tossed around in a car to/from York.  I fixed my most recent problem that way;

2) the handrails are the antennae, and they need to be properly seated in the isolating fittings (at the front of the boiler)- this can be tricky to get right when you reinstall the shell;

3) Mine had the opposite problem of not moving at all - it turned out to be a bad control or "mother" board.  Needed to send it back to Lionel for that.

Good luck!!  Really great engine once you get it going!

Hopefully, the issue is resolved, but I am not sure why or if the "fix" actually worked or coincidentally worked.

  After doing the continuity checks on the antenna system ( no problems indicated by ohm meter), making sure the boards were seated, and inspecting for any electrical connections that may be loose, I but the engine back together with the best of hopes. Bill, I concur with your thoughts on reinstalling the front part of the handrails

  Upon powering up the TPC 400, the engine lurched forward with no control.  The engine was seeing the full voltage. Hard to try a reset with the engine racing down the track.

The light bulb moment.  To Self:  Why not set the TPC output to a lower voltage.  7 volts worked well.  I set the engine command switch to program and switched on the power to the isolated siding.  Engine moved forward at a slow speed.  Hit the aux 1 boost sequence on the legacy controller for the reset.  Put the engine switch back to run, and all is operating as it should.

Since the earlier days of people having runaway engines due to loss of signal from the command base, my engines that are not actively being used sit on electrically switch off sidings/storage tracks.  Thankfully, I have a conditioned reflex on the halt button.

The suggestions all of you offered were put to good use and appreciatively added to my knowledge.  Folks such as your selves make this forum rock.

Thanks again for your support,

Chris Cook

AN update the operational abnormalities of my 844.It is now stuck in reverse, and races rearward for a few seconds to about a minute before it slowly slows down and drops into command mode. Then all of the command functions work in reverse, but the engine will not move forward.  The rear tender light does switch off when a forward command is sent

For the purposes of adding to the knowledge base of the forum and also to recognize that some of the more technical minded frequent posters have pointed out the same possible electronic issues in various threads, I have copied the response from Lionel:

Christopher,

A few other things to have a look at that may cause this issue. If it is darting down the track without any command to move sent you could be looking at a R4LC issue or a DCDS issue. The R4LC is the receiver and acts as the brains of the operation telling everything in the loco what to do. The DCDS is the motor driver. The R4LC talks to the DCDS via a serial wire. If this wire becomes loose or disconnected it will not know what to do and could dart down the track at any time. If the command to move is sent and it darts down the track you could be looking at a flywheel sensor, DCDS or I have seen a few loose flywheels causing an issue like this.

I will be doing a finale check, then most likely will request an RA for repair. If I had a spare R4LC board, I would give it a try.  It may be worth ordering , since shipping and insurance is about 70 dollars round trip.

Hope the information is beneficial  to the group.

Christopher Cook

The loose flywheel could be a factor, or the flywheel not properly spaced from the sensor that's mounted on the motor.

Gunrunnerjohn:

  I took the shell off.  I presume the sensor is the part with the symbol of a diode on it.  A small white bar symbol in front of the diode symbol is position directly over the holes in the squirrel cage.  The cage is approximately 1/16 inch from the motor mounted circuit board.

The flywheel and cage are secure.

  Before removing the shell, I powered up the 844.  As the engine ran in reverse with 4 volts applied to the track, the whistle, bell,crew talk etc all worked. Speed control and direction did not. The r reset symbol on the legacy screen was activate, the engine signaled it was received, but nothing changed. I dropped the track voltage to the point of the engine coming to a stop.  I then raised the  track voltage and although the engine would only operated in reverse, it was now under full command control.  Maybe this points more to speed sensor or motor driver issues.  Your thoughts on this would be much appreciated.

Chris

Thanks for the input GGG

Back to the bench for me to implement the advice

Chris

The fact that it runs in one direction seems to suggest a control issue, that would likely be the DCDS I would suspect.  Since there is some control over the serial link, I'm having a hard time with the R4LC being bad and only affecting forward commands.  I have seen on very rare occasions a speed sensor that only worked in one direction, but that's the exception and not the rule.  My suspicion is the DCDS board if you don't find any wiring issues.  Obviously, if I had it in hand, I'd swap the R4LC first as it's very simple to do, but my betting is on the DCDS.

Question.  When it starts flying down the track, does the reverse stop it, or do you have to power off?

John,

When it is flying down the track, reverse does not stop it.  Eventually, a few seconds to a minute, it will stop on its own.  When I first had the problem, It would only go forward in both command and conventional.  It now will not go forward or reverse in conventional.

Chris

If it stops on it own you will probably need a motor sensor.

Bill 

That would be the best case Bill.  I had one that did that, and it turned out to be the DCDS sadly.

All great information from the guys.  Here is something I have run into.  If someone picks the locomotive up and squeezes the handrails, the handrails pop out of the insulated bushings on the pilot deck.  The bottom of the handrail finds ground and you are not going to be able to run the engine in command.  Replace in bushing and you are good to go.

Take your continuity meter and put one probe on the antenna and the other on ground.  Use the siderods for ground.

   Go to this after looking at what the guys posted on.

Thanks for all the suggestion from everyone, but nothing has changed.  I just "fired" it up again. As it has been, it traveled in reverse for about 25 seconds this time and came to a stop on its own.  It then operated in command, but only in reverse.  I can power down power up as many times as I wish, and it will come up in command.  However, if the engines sits for an hour or more unpowered, it will again race of when its powered up.  One might assume a cap is slowing bleeding off during an extended shutdown period?

Marty:  I metered the handrails and they are not grounding out.

  As it stands now, it is headed for the repair shop. Lionel at 800 miles away, or the nearest authorized repair shop, Charles RO, about 90 miles.  

Chris

Chris, if it goes to Charles Ro, I will end up with it.  Bill, I am with you on the motor sensor.  I have worked on several of those early Legacy engines and the DCDS is less of an issue than the sensor at the flywheel.  Chris, did you meter the handrails to pin 23 on the R4LC?  If you have not done that, put you R4LC probe on the back of the board.

Marty

  If looking from the front of the engine to the back, pin 23 is the one on the back row last  on the right, then yes.  I got continuity verification from the handrails to the mother board connection, and then from the handrails to the pin connection.  I used a pin chart that Gunrunnerjohn had posted in an earlier  thread.

   Now that I think about the purchase of the engine from a gentlemen in the orange hall this fall, he did say you were one of his go to people for repairs.  

Chris

Chris, pull the R4LC and look at the back.  tThe side that plugs into the 24 pins from the motherboard is the front.  The bottom pin on the bottom right is pin number 1.  That can be identified by a square pad on the board.  From the BOTTOM right, pins are R-L 1-23.  The top row are from R to L pins 2-24.

Marty:  Thanks explaining the pin numbering sequence on the R4LC.  I am now sure that I tested for continuity from pin 23 to the handrails.  I use the audio response on the ohm setting of my digital multi meter.  The continuity is there.

Chris

WOW! THANKS to all, I was having to reset my 844 and still having problems but after reading this thread I fixed it and working like new now.          TRAIN NERD AL

Train Nerd Al:

  It is great to know that the power of this Forum helped you to resolve an issue with your 844.  Please post the problem you encountered and the remedy that fixed the problem.

Chris

Well, I was always having to reset & finally the reset didn't work, the cab would flash and then would do nothing not even move. Looking close at the hand rails I just pushed them back towards the cab and they moved, not much but enough. Also made sure nothing was touching them anyplace and worked GREAT!     Train Nerd Al

I Hit the engine with the meter to find 5VDC going into the driver board and no 5VDC coming out to end up at the flywheel encoder.  Replaced the DCDS-J and life is good again in 844 land.

That is an early Legacy locomotive with modular boards.  I have run into two in the past that did not produce 5VDC into the DCDS-J and it turned out to be a defective 5 volt regulator that mounts on the motherboard.  Motherboards are cheap and an easy fix. 

When troubleshooting these engines, I look for the 5VDC first at the flywheel encored.  If 5VDC is not present there, I go next to the output from the DCDS-J.  If none there I go to the DCDS-J input.   If the DCDS-J input does not have 5VDC the next stop is the motherboard.  The meter is then put on the positive leg of the voltage regulator to look for 5VDC.  If no voltage there, the motherboard needs to be replaced.  Lionel does not recommend taking 5VDC from pins 19 and 20 on the R4LC.   On TMCC engines with an external voltage regulator and a similar issue, if you do not have 5VDC going into the driver board, you can take it from pins 19 and 20 on the R4LC.

The R2LC has a very anemic regulator, so powering anything but the IR tether with it is probably not going to work.

John, on TMCC that is a standard practice.   It works and works perfectly.  TMCC only and not Legacy.

I'm surprised the anemic little TO-92 regulator is happy with that.

John, give it a try when you run into this situation.  That has been authorized by a higher power than all of us.  It works great.  That crazy regulator was used on many of the later TMCC engines.  When I see the brown wire (from reg) going into the DCDS I go right for it looking for the 5VDC. 

Higher power?  Maybe one that just knows more.