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I have the k-line greenport scoot Long Island railroad o scale train set. The MP-15 Diesel engine is not operating properly. At first it was having a tough time pulling the trains. Then I noticed a burning smell from the engine. Now it doesn't run. At time it will only go backwards. Power seems to be going to the engine as the light in the cab goes on when I put the power up. I've cleaned the wheels and tracks and lubed the gears. Any suggestions or input would be much appreciated.

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taki53-

 

K-Line made two versions of the LIRR MP-15 (one with horn and a series/parallel run switch, and the other without), but in either case it sounds like an electrical short within the locomotive caused the problem. The overload likely burned the wiring, which would explain the smell you observed. At best the overload charred a few wires, but it is also likely that the reversing unit and/or one (or both) motors was damaged.

 

Fortunately the MP-15 is a very easy locomotive to troubleshoot and service. Start with removing the shell - disconnect both handrails from the cab (they pull out of the hole with little pressure), and unscrew the Phillips screw on the front of the locomotive close to the frame. Once removed, slide the entire shell forward, and then up. With the shell removed, look for wires that are charred and/or have melted insulation, then examine the reverse unit circuit board for burns and evidence of exploded components. Also check to see if any of the soldered connections are broken, or if any of the wires have exposed insulation.

 

If everything checks out above the frame, turn your attention to the trucks. The trucks are secured to the frame with horseshoe clips; using needle nose pliers or a similar tool, stretch the clip to release it from the stud. I would recommend doing this with the locomotive on a flat surface because the clip is the sole means of holding the truck to the frame. Although mechanically detached, the trucks are still tethered to the frame by the the motor, third rail pickup, and ground wires. Four screws hold the truck frames to the truck (two of the four secure the pilot and coupler); remove these to expose the wire connections and the motors. Note the motors are horizontally mounted and that the truck frames are metal; it is possible that one of the motor wires touched the metal frame, causing an unintentional ground. With the frames off, look for more broken/melted/charred wires and replace with new wire as needed.

 

If everything still looks normal, try troubleshooting the motors. Note that these motors are DC, which means a regular AC transformer cannot be used. I recommend using a 9V battery with a snap-on connector (Radio Shack part #270-325 or equivalent). Touch one lead to each motor post to see if the motor spins; reverse the leads and the motor should spin in the opposite direction. Repeat for the other motor. If both motors are working normally, then the reversing unit circuit board is likely the culprit. Replacing the e-unit is easy, but you will have to solder the wires from the new board to your existing harness. Its best to make a diagram, then go wire by wire.

 

Although K-Line is out of business, parts are still readily available from Brasseur Electric Trains. The reverse unit is part number K2200-E001; if needed the motor part number is K2200-E002. Brasseur also has other parts for your MP15, including the weight set, couplers, horn, bell, and more.

 

I've worked on MP15s before, and I can make the repairs if you prefer.

 

Hope this helps!

 

-John

 

I'm also experiencing this issue with my K-Line MP-15.

Engine details:

- Union Pacific, #1506

- K-2200-8 stamped on the bottom.

- Only one switch on the bottom. Has no labeling, but I assume it's for direction lock as opposed to series vs parallel. Switch position seems to have no effect on getting this thing to go forward.

I tried the test with connecting a 9V battery to each motor, and each moves forward, or in reverse when the wires are swapped (and both get powered on and move at the same time with this battery test, btw).

My question is, before I consider replacing the whole e-unit, would disconnecting the two white wires for the direction lock switch be a valid troubleshooting test, in case it's bad? Can this particular engine run fine in forward/neutral/reverse without it being connected?

Otherwise, I'm not seeing components that look burnt, nor do I see any loose connections at solder points, or anything that looks like it might be shorting concern.

k line mp15 electronics

 

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Last edited by sinistar

The reverse board is a cheap component, I'd just replace it.  If you're looking for suspect components, I'd say the four NPN power transistors would be my top suspects.  That 2SD880 is fairly low rated for the task, and a motor stall can cook them.

I have one of those boards from an upgrade if you need a replacement.

Last edited by gunrunnerjohn

The reverse board is a cheap component, I'd just replace it.  If you're looking for suspect components, I'd say the four NPN power transistors would be my top suspects.  That 2SD880 is fairly low rated for the task, and a motor stall can cook them.

I have one of those boards from an upgrade if you need a replacement.

Actually, out of curiosity, what was the upgrade you did? Rather than just replace like-for-like, it would be cool to update this thing to at least have a bell and horn, if the cost gap isn't too huge and the swap isn't too complex. Objective is to run it in conventional mode only.

Last edited by sinistar

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