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I have an MTH MT-3020LP whose fan is not working. I took the fan out and tested it and it works so I'm thinking it's the CV board but I don't believe that board is available anymore. Is there a way to test the board? Can anyone help me determine if I'm correct and maybe how to fix it.? Thank you

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There is a switch under the locomotive for smoke on/off .......I’d start there. Those PS1 smoke units are pretty stout units. Just because you tested the fan motor, and it spun, doesn’t necessarily mean the motor is good.....if the motor requires more oomph to get it going, the board may not supply enough power to make it spin.....but I’d check the switch and verify power to the board for starters .........Pat

Thanks. Maybe I should have been more clear with my question since I am new to repairing MTH. I am old Postwar Lionel guy. To be able to test the smoke fan plug, I need to remove the body. Since the body appears to get power through the plug from the tender to the chassis, do I need to connect jumpers from the chassis to the body in order to complete the 6v bulb test? If you could outline the steps I need to take, it would be very helpful.

OK, Since this engine has the smoke unit mounted in the shell, you could trace the red AC power wire from the spring pad on shell and then just jumper track power with leads to the red wire, and also the shell as chassis ground.

PS-1 smoke units get track power from the engine, not via the tender.  The harness sends AC power to the tender for the circuit board.  Only motor power comes back to engine.

The Yel/Wht wires to smoke fan have a plug.  The other plug typically is red/black AC power to energize the smoke unit PCB.  Sometimes it can be soldered wires but most are 2 pin molex.

But since it is not working, just take it out of the engine and power it up with AC on the bench.  Visible inspection may show your issues.  G

OK I took the body off again and observed the following. Wires on the cab going to spring pad are orange and blue. When power is put to orange with ground on body all bulbs on body  light up but no power to fan. I also tried power to blue wire with ground on body and no bulbs light up and no power to fan. The connector to the fan has yellow and blue wires while the spring pad on chassis has dark blue, brown, yellow, and light blue. The CV board has 2 connectors 1 white and 1 red both with black wires on them (body bulbs?)

Why are we talking about the lighting CV board vice the Smoke board when the issue is no smoke fan?????  Only the very earliest MTH using a Seuthe smoke unit NO FAN were plugged into the CV board.

Early stuff could use different color wires.  Usually Orang Center rail and Brown ground.  On the spring pad one is AC up to the Light CV board on all the time.  The other is AC up from the Smoke switch.  Powered on by the switch.  Both get power from the engine center rail red.

You need to remove the smoke unit from the shell. Usually one screw to the bracket on PR steam.  Though some articulate use 2 screws.  Smoke unit comes out whole and you unplug the connector on smoke unit that has wires going to spring pad.   G

Well, it was a combination of things (I think). I replaced the fan motor and could get it to work without the housing being screwed to the board. Then I thought it was the wick keeping the fan from turning, then I thought the fan blades were too high so I pushed them down and it worked. Trouble is any one of those things could have been the culprit right from the factory? My lack of experience/knowledge with new MTH didn't help.

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