Erratic smoke and chuff sounds on Lionmaster PRR T-1 Duplex

My Lionel  38020 Lionmaster  PRR T-1 Duplex works fine in Legacy Mode  except that chugging sounds and smoke shut off for a few seconds at a time and then restart.  This even sounds realistic sometimes as prototype steam locomotives do this too.  But it happens constantly every few seconds.   

I already replaced the cherry  switch and also the infrared sensor assembly and sensors between engine and tender but this did not solve it.  

Any suggestion s would be helpful.  Phil



Original Post

Top suspect would be the alignment of the IR sensors.  You may have to do some adjustment on the chuff switch as well.

Of course, there's always the possibility that the wiring has a problem from the chuff switch to the motherboard where the R4LC lives.  Since the chuff switch is on a articulated truck, those wires get flexed a lot.


The adjustment of the cherry switch is critical on this end. You might check the 4 lobe cam on the drive wheel, might be cracked and spinning on axle.  Cherry switch I believe is on the rear truck .


tca 75-8237

LCCA 2308

Authorized Lionel independent service station

I opened it up again and the cam is not loose.  When I put it back together and tried it for the first time, chugging and smoke began but within seconds smoke and chugging stopped and the engine continued running with constant steam sounds.   Might there be a problem in the motor driver board, 691dcdsje101428 into which the wire from the cherry switch is plugged in?  I will mention something else that may be related.  The smoking whistle including both fan and smoke output, on this engine simply does not work from time to time, but most of the time is ok.  Everything else works, bell whistle, talking, etc.  

You have posted the Lionel TMCC number for the locomotive, what's the real number.

Pennsylvania LionMaster TMCC 4-4-4-4 T-1 Duplex #5514 SKU: 6-38020

Could we perhaps really be talking about this one?

Pennsylvania LionMaster LEGACY 4-4-4-4 T-1 Duplex #5511 SKU: 6-11207

I wouldn't start replacing $110 parts until I was sure that was the problem.  Since this is obviously the Legacy version, the adjustment of the Cherry switch is pretty critical, I'd revisit that.  The smoke chuff stopping suggests that it's in the locomotive and not the IR link.

John:  It definitely is a 11207 Prr T-1. An hour ago, I removed the cherry switch, put the motor and truck back together and put the loco on my rolling test track.  I kept the wire going from the motor board to the cherry switch attached so I could hold it in my hand and test operation.   the  other wire on the cherry switch I put to ground,  No response when I moved the flapper by hand .  Prior to doing this, I did find continuity between cherry switch output and the motor board,  The needle on my meter would jump around as the loco ran on its rollers.  Any  chance I have the cherry switch wired wrong.  From left to right with the flapper pointing down to my right  the pins from left to right are as follows. 1and 2  are crossed by a capacitor.  2 also goes to frame of engine and pin 3 goes to motor board.  There is a board under the motor board that I suspect may be involved.  Any thoughts.  Phil

Since I don't have one to look at, I can only say that one wire MUST go to the COMMON terminal, and I presume one would go to the NORMALLY OPEN, though it will probably work on the NORMALLY CLOSED as well.  I haven't had mine open in a long time, so I don't have an actual visual reference to go by.  Below is the switch with the contacts identified.


Photos (1)

John:  Is the capacitor on that cherry switch important?  I am using the original capacitor  on a new cherry switch.  Also, since the cherry switch has a wire going to the frame of the loco, I assume that the output that goes into the motor board is a ground that momentarily pulses.  .  Am I correct here?  What happens next; I suspect there may be an issue with plugs or loose wires within the motor board or the board directly below it that has lots of connections for couplers, smoke units, etc.  I have not removed these boards yet to check for problems but would this be a good idea?  Phil

The cap should be there, and yes, it grounds to the frame and pulls the input down to trigger the chuff.

I'm not sure what problems you're going to spot, you're likely to do more damage removing boards than good unless you're going to test them externally.

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