# LGB issue: Engine shorts out while moving forward



## Leland Limited (Nov 10, 2010)

I have an older LGB engine (2076D) and am having an issue with it moving forward. I'm using standard dc power with an mrc transformer. The engine runs perfectly while running in reverse, but when I switch it to the forward position, my engine's lights dim and it crawls forward for a few seconds before shorting out my transformer.

I am wondering if replacing the motor in the engine will correct this issue, or is this a more complicated issue with the on board circuit board in the engine?

Any advice would be much appreciated; thanks!
Mike


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## Dan Pierce (Jan 2, 2008)

Possibly out of quarter and sensitive to one direction only. Likely cause 

Or, shorted front light, only used when running forward. Doubtful this is the root cause as diode should burn up. 

Bad motor possible, especially if bearings are bad. Motor shaft should never move, just turn. Seen this happen several times. 

Or, gear slipped on axle and only one direction would cause a problem. (seen this 3 times on 3 different model LGB engines).


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## Leland Limited (Nov 10, 2010)

thanks for the response dan.

do you think that replacing the motor with a new one would likely solve my issue? i'm a newbie, and do not understand what you mean by "out of quarter".

i do not really know how the lgb motors work, but find it odd that the motor works perfectly while running the engine and lights in reverse but completely shorts out while trying to move forward. can motors malfunction that way?

thanks again!
mike


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## Curmudgeon (Jan 11, 2008)

Maybe. 
The older lgb motors were not internal thrusted. 
Some the ends of the shaft rubbed on plastic blocks that can wear out. 
Some rubbed against a single bearing ball in a pocket at each end (and, if you've opened it, and lost one.....). 
Sometimes, without those retainers, the armature can and will move a long way, once they have run without external thrusts for a period of time, and possibly short the commutator or windings when the armature moves to one end. 
New replacement motors are internally thrusted, and external thrusts can be eliminated or ignored. 
One way to check is to set the engine up to run forwards, apply power while pushing the engine forward (keeps the torque of motor/wheels/gears from pushing armature) and see if it runs okay while keeping the load off. 
If it does, you can eliminate the on-board wiring/lighting. 

You don't have anything plugged into the socket plugs in the back, do you?


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## Leland Limited (Nov 10, 2010)

i did solder an extra led with resistor into the back socket plugs. since my issues began, i have unplugged the back circuit board (the one that has the 2 reverse lights as well as the cab light). the train still stalls and shorts out while moving forward.


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## krs (Feb 29, 2008)

I think you need to take out the motor and test it by itself to see if it runs properly in both directions. 
DEpending on what you find, that will determine what else to look at. 

General question: Did you get this loco with this problem or did it run fine in both directions in the past and now there is this problem?


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## Leland Limited (Nov 10, 2010)

Yes, the engine worked fine in both directions for the past 16 years until yesterday. The engine worked with the new led for awhile too. I ran it for around an hour last night, and that's when the trouble began
Thanks again for all of your experienced advice.


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## krs (Feb 29, 2008)

Sounds af if you think the LED you added has something to do with your problem. 

When was the engine manufactured? 
Is the OK sticker still attached? Just post the six digit number on the OK sticker here so we can decipher the manufacturing date - that provides some clues what circuitry is inside the loco that may have been damaged.


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## Dan Pierce (Jan 2, 2008)

A motor that has worn bushings/bearings will run out of the engine just fine. 
You must check each end for any movement of the shaft. Under a load the shaft will move if worn and the armature shift and jam, and in only one direction. 
Also note when replacing a motor that the contact end has an alignment pin which serves to make sure the engine will run in the right direction when installed. 
If inserted wrong, the gear box does not assemble properly and the gears will strip.


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## stevedenver (Jan 6, 2008)

i think dan has it nailed 

i have a couple of these and i too have a thought yours might be out of quarter- 
or the axel gear has worn- 
(this is what happend to mine and the symptons were very subtle-but the direectional issue sounds familiar) 

in my case nothing was apprent-no visible wear 
when properly quartered it would slip a few teeth even under light load -one direction only-forward 

if your loco seems to bind going forward-which would load the motor and perhaps the board- 
then 

i too think you should test the motor and if its fine-im guessing it could be the gears and or the entire motor block/box after 16 years -or perhaps as dan has mentioned -the motor as well

fwiw i changed several parts with new ones on my trusty old sandwhich motor box 2076 

-and to my dismay -some of the older parts are not quite a fit with newer-there seem to be slight changes which prevent mis-matched parts from working well together- 

after paying for a variety of new parts-had to get an entire new block gears etc to make it right- 

so you might simply consider train li for an entire new box assembly with drivers etc if this is the issue


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## George Schreyer (Jan 16, 2009)

Some LGB locos use different internal regulators for forward and reverse. It is possible for one of them to have died. However, considering how old your loco is, mechanical wear is more likely.


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## Leland Limited (Nov 10, 2010)

Thank you all for your replies and suggestions; you guys are definitely a great source of information.

I got to the bottom of my train issue; it turned out that I had a blown resistor on an installed sound card. Once I uninstalled the dc wires leading into the card, my train returned back to normal operating conditions.

The folks who built the card are speculating that I had a power surge as I was charging up the card's attached battery. I'm hoping they are correct, and I'm looking forward to getting the sound card repaired and reinstalled.

Thank you again!


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## Dan Pierce (Jan 2, 2008)

Very interesting find. 

It pays to disconnect everything in order to solve a problem.


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## John J (Dec 29, 2007)

When in doubt.....Cut it out


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