Large Scale Central

LGB Forney...Dead power pick-ups

Problem Solving
#1

I have an LGB Forney that only picks up power from the rear truck. The drivers and skates have no power connection to the motor (verified by multi-meter).

In the picture below you can see the long pins (111 and 141) connect all the driver brushes and skates but there is no connection to the motor leads (pins 112)

Per the exploded parts diagram nothing appears to be missing…

Pins 112 (2x) contact the motor +/- tabs (verified as I tore down the motor block).

Pins 111 and 141 connect the brushes and skates but nothing appears to connect either of these to pins 112.

The diagram is for a sound equipped version I do not have. The four wires leading to the power-block are all black.

http://www.lgbworld.com/service_manuals/20252-1.PDF

I am thinking of soldering a jumper between these pins (one on each side connecting pins 111 and 141 to their closest pin 112). I will likely do this at the connector.

So what is missing here? My Mikado has two brass strips that make this connection but none show up in the parts diagram for the Forney.

#2

Of course if nothing is truly missing then it is possible my main board is bad. It’s also possible that shorting the pins 111 and 141 to their respective terminals on the motor could result in “magic smoke”!

#3

I have an LGB 2-4-0 which appears to use the same motor block with different axles,

Be aware that it does have sound, but I feel the wiring diagram would be similar (haven’t actually looked at your PDF, going with what I know).

Pins labelled 111 and 141 are power from the track pickups up into the locomotive. There should be a plug on top of the motor block with FOUR wires going to it.

These pickup wires go to the main circuit board OR the power on/off switch (again, I’m assuming the Forney has one–the switch which toggles the lights/motor on and off?). From there, wires return to the motor block through the other two wires on the plug and connect to pins 112. These pins contact the power supply tabs on the motor, one on each side. This allows the motor to be shut off, as all power leaves the motor block but only power intended for the motor returns.

Connecting pins 111 and 141 to 112(x2) would ensure a connection into the motor, but would eliminate any ability to shut off the locomotive on DC track.

I can draw a diagram if that doesn’t make sense–I’ve torn apart the 2-4-0 and added a switch so I can run either track or battery power by running power directly into the stock pickup point before the circuit board, allowing the sound/smoke/lights to function on battery. As such I feel I have a reasonable grasp of how these blocks work.

#4

Thanks Robbie, what you say makes perfect sense and kind of what I expected. I’m pretty sure I have an issue at the switch or PC board. Yes, I am familiar with the connector, that is where I will add the jumpers. Never occurred to me the 2-4-0 would use the same block,

Looking closer I also noticed the headlight is rather dim, even at full power. Clearly something is amiss internally but as parts seem impossible to find I have little choice but to make the connection and run it. Maybe some day I will tear it down and see if there is a true fix but without parts I doubt it.

Thanks for the reply!!!

This would explain why I was able to get a NIB old stock LGB Forney for $250.00. Would love to go back and change that feedback now!

:slight_smile:

#5

Mark V said:

Thanks Robbie, what you say makes perfect sense and kind of what I expected. I’m pretty sure I have an issue at the switch or PC board. Yes, I am familiar with the connector, that is where I will add the jumpers. Never occurred to me the 2-4-0 would use the same block,

Looking closer I also noticed the headlight is rather dim, even at full power. Clearly something is amiss internally but as parts seem impossible to find I have little choice but to make the connection and run it. Maybe some day I will tear it down and see if there is a true fix but without parts I doubt it.

Thanks for the reply!!!

This would explain why I was able to get a NIB old stock LGB Forney for $250.00. Would love to go back and change that feedback now!

:slight_smile:

I’ve seen several for that price on eBay, buy it now, and wouldn’t suspect a thing if I was in the market for a Forney.

I’ll have a look at the wiring diagram later today and see if there’s anything I may have missed. In the meantime…the last exam of my college career is in an hour or so and I’m gonna go worry about that for now :slight_smile:

Oh, and I’m told the Forney can outpull a Mogul. Enjoy that.

#6

I’d buy another in a heartbeat at $250.00…Good luck on your exam!

#7

Soldered at the motor block connector…Running like a Swiss watch (or running like an LGB engine).

:slight_smile:

#8

Glad you got it running. I love my Forney and it runs/pulls well. Eventually I want to convert it to battery power.

#9

The LGB board in some Forneys have a separate wired connection for the motorized truck and the rear wheels. And there is a 4 position switch for disconnecting motor to wheels for an MTS add on board (55020/55021). Perhaps this unit has had the MTS removed and the switches were never set to DC which means they need to be on, for DCC, and open (off for MTS/DCC).

I have seen this many times on used equipment.