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8142 Repair

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  • Member since
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8142 Repair
Posted by gottcent on Tuesday, September 18, 2012 8:53 AM

I've taken apart a Lionel 8142 early-MPC steam engine that refuses to run. The light and smoke system work, and the 2-position e-unit appears to be working properly. When power is applied I can hear the familiar buzz from the e-unit solenoid, but the train will not budge in either direction. I took apart the motor and found that the armature tests out OK (electrical continuity among all 3 commutator faces and all 3 isolated from the center post). I cleaned the commutator (including the slots between sections) and the brushes and brush wells. The only odd thing I found was that one of the brushes seems to stick in its well instead of moving up and down. (The other brush moves more easily). I cleaned out the wells with TV tuner and Q-tips, but the one still sticks a bit. However, the motor still will not run. I can't find any missing or broken wires. Any suggestions?

John Gottcent

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Posted by cwburfle on Tuesday, September 18, 2012 10:04 AM

If one brush is sticking, that could be the root of your problem. You can try using the tip of a pencil or something similar to gently press down on the sticking brush while power is supplied. If the engine starts running, then you have identified your problem.

Otherwise, it is somewhat common for motors with 2-position e-units to have issues with the wiring to the field coils. On your engine, there are actually two seperate sets of windings wrapped around the field. Only one should be active at any given time.
On one end, both wires are twisted together and attached to one of the brushes.  On the other end, the wires are seperated, with one going to each terminal on the 2-position e-unit. Make certain the wires are attached as described above, and that the wires are not touching eachother, or any part of the frame.

You can try touching one test lead to a pickup roller, and the other test lead to one of the e-unit terminals. Let us know what happens.

 

KRM
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Posted by KRM on Tuesday, September 18, 2012 10:39 AM

I have that same loco and it is not of the best quality. I also think you should find out why that brush is sticking.

Best of luck. I took mine off of the table and use the old post war locos now. Much better engines.

Joined 1-21-2011    TCA 13-68614

Kev, From The North Bluff Above Marseilles IL. Whistling

 

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Posted by cwburfle on Tuesday, September 18, 2012 11:24 AM

Each of my two sons was given an 8142. While one had a bad sound of steam board, both engines have always worked fine. I found a junk tender to replace the bad board.

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Posted by cwburfle on Wednesday, September 19, 2012 5:03 AM

In my previous post I mentioned having an 8142 with a bad sound of steam board. Unfortunately, this is a very common problem.
If you have a good sound of steam tender, there is preventative maintenace you can do that should prevent the board from failing.
The problem is generally thought to be caused by the decay of the foam strips that are used to mount the board. Eventually the underside of the board comes in contact with the metal frame of the tender, and shorts the board, spoiling it.
The solution is to put something under the board to prevent contact.
I like to cut pieces of illustration board (thick cardboard with a hard finish on both sides).

Sound of steam was an early sound system, and is relatively crude, but I like it.

 

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Posted by gottcent on Wednesday, September 19, 2012 8:59 AM

Thanks for the tips, guys. I tried pressing down the brushes with the handle end of an artist's paint brush, but nothing happened. I am wondering about inadvertent grounding of the coil wire connections to the e-unit, however. The wires are arranged as you said they should be, but at the e-unit end, where they seem to be plugged in to connectors protected by insulators, one of the insulators seems to be pulled away from the metal frame of the e-unit. I used an ohm-meter to discover that that lead remains connected to ground, even if the reversing switch is pointed toward the other lead. Should this be so? I tried pulling the plug out of the "faulty" socket but couldn't get it to budge. I'm thinking of unsoldering that lead to see if that would allow the motor to move in one direction only. Am I right in thinking that if my suspicions are correct, that should work?

John

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Posted by cwburfle on Wednesday, September 19, 2012 9:55 AM

Let's make certain we are "talking" about the same thing.  There are two terminals sticking out of the side of the e-unit. These terminals are where the individual wires from the field coil should be going.
As far as I can recall, there is no plug, the wires are soldered directly to the terminal.

If one side terminal is always grounded, then your motor should run in one direction, but not the other.
You can try disconnecting the wire that is always grounded. When the other wire is grounded the motor should run in one direction.

Be aware that all the terminals on 2-position e-units, such as yours have all the terminals set in plastic that is senitive to heat. Be careful to work quickly, and not let the terminals get too hot.

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Posted by gottcent on Thursday, September 20, 2012 8:47 AM

I think we are talking about the same terminals--the two coming from the side of the e-unit to which the single leads from the coil are attached. The reason I mentioned plugs is because the parts diagram in the Lionel Service Manual I have identifies those coil leads as terminating in "Male Plugs" to be inserted into the insulation protected sockets on the e-unit frame. But closer examination of the actual scene suggests that you're right and that the leads are simply soldered to the terminals.

I am going to try disconnecting the coil lead wire from the side that always seems grounded. I was going to unsolder it but given your helpful warning about the heat-sensitive plastic in the area, I think I will clip it instead. The lead seems long enough for me to be able to re-attach it with a quick soldering job if this test doesn't get anywhere.

I appreciate your help and your patience with this. I probably won't get to work on it again until the weekend, but I'll let you know what happens.

John

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Posted by gottcent on Friday, September 21, 2012 10:54 AM

Well, I tried disconnecting what I thought was the faulty coil lead to the e-unit. Nothing. Then I reconnected that and on a whim tried disconnecting the other lead. Again, nothing. I even went back into the motor (where one brush was sticking) and replaced both brushes with new ones that move up and down appropriately in their wells. Still nothing.

I appreciate all your help, but I think it's time to send this motor to the local hobby shop to see what he thinks.

John

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  • From: South Carolina
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Posted by rtraincollector on Friday, September 21, 2012 3:19 PM

Not sure what your local hobby shop charges to repair an item but if I'm thinking of the correct engine you can get them on ebay for about $35 - $50 including shipping a lot of time may be different number but heck just change shells  and you probably come out cheaper than your local hobby once they add labor and parts

Life's hard, even harder if your stupid  John Wayne

http://rtssite.shutterfly.com/

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