I snagged a Lionel Legacy B&O Mikado (6-11280) off ebay for a good price. It was listed with a bad smoke unit, which can easily be fixed. I tore down the smoke unit, measured the resistor, tested the motor, replaced the wick, and checked the wires and pcb for continuity. Everything looked fine, so I put the locomotive back together and put it on the track. The locomotive smoked in idle, but when I put it in gear, the smoke stopped and I got the three blinking lights.
I have the smoke unit in front of me now. I am going to re-flow solder to all connections in case there is a cold joint, lubricate the motor, and clean up the residue on the resistor.
Will the resistor in the smoke unit still measure in the 8 ohm range if it went bad? I did get smoke last night, so I don't think that is the problem. Could there be a fault in a pcb or wiring upstream? Any thoughts or suggestions would be appreciated.