MTH PS-2 GS-4 #4449 quit smoking

Call MTH they will know.

if the element is getting hot n not smoking you might need   to replace the wick if the wick is brunt up it will not smoke very good if not at all and wicks are very cheap only a few bucks each! take the engine  apart and inspect the wick if burnt  buy a new one n replace also the resister might be getting hot but not hot enough to make engine smoke disconnect the resister plug from the ps board connector and check the ohm resistance and let us know what it reads on ohm scale continuity!

Forum member GGG troubleshoots and repairs these.

If the smoke fan isn't running, and the motor is good, it's either wiring or the board.  One thing to check, how much current does the smoke motor use at 5V?  If it's more than about 40ma, the motor is bad.

The smoke motor seems o.k.  It appears to me that the issue is with the board that controls the motor, as the motor is not getting a signal to kick in and push the smoke out.  The wick looks fine, and the element still produces smoke, which stays in the stack.

Check the continuity of the wiring from the smoke motor to the 4-pin connector on the PS/2 board.  If the wires make it all the way to the connector, the next step is to replace the smoke motor FET on the processor board.

Thanks everyone for your helpful hints on what to look for in my MTH engine that quit smoking.  I tried a couple of fixes and set it aside for a few days.  I know you like updates, so this morning, with the engine still sitting on the track, I thought I would give it a try with my DCS WiFi Explorer.  Low and behold, it ran well and smoked like crazy.  The nighttime train genie must have been at work!  Now I'll probably never know what was wrong with it unless it does it again.