Lionel TMCC J Fan Driven Smoke Unit

What resistor is in the smoke unit? If its a 6 ohm resistor you should replace it with an 8 ohm resistor as the 6 ohm resistors have a reputation for eating AC regulators. Another possible culprit is the wires going to the fan motor may need to be re-tacked with fresh solder or replaced. A similar thread for these problems popped up a while back and here's the link for it, hope this helps.

https://ogrforum.com/...ke-unit-troubleshoot

@Peter B Thank you for the tips. Yes I did replace the 6ohm resistor with a 8 ohm. I also did look at the discussion you linked thoroughly last week (which gives me some relief we are on the same page haha). I will check the fan leads again. when testing with a battery the fan works A Ok. Just when put back together I wont stay on but for 2 seconds.

Sounds like the power supply for the fan on the smoke unit is the issue.  Check the 5V supply, it's pretty simple, a diode, cap, and the 3-terminal regulator.  My guess is it's either the cap or the regulator that is crapping out.  Many times the cap comes loose from the board, that would cause a brief burst of power from the regulator and then no voltage.

@gunrunnerjohn Thank you very much for the info, i was hoping you might look at this haha. Just to clarify the supply in question should be .....

correct?

No, actually the regulator components I speak of are on the smoke unit PCB.   You can see the large cap I speak of in the picture from the exploded parts view.  The regulator and diode are close by.  I don't have that exact smoke unit to look at, so without seeing it, I can't be more specific.

So I am still having no luck. It appears the power supply checks out. I have now tested with 2 new PCB boards and no luck. Again the only time the fan kicks on is for a second or two when on my legacy remote I hit the plus button a few times to turn on the smoke unit. Again I have new PCB and AC regulator on this loco. Any suggestions?

Well, the regulator could still be bad.  I've gotten new ones that were defective from Lionel, it happens.  Make sure there is voltage on the smoke unit itself.

@gunrunnerjohn posted:

Well, the regulator could still be bad.  I've gotten new ones that were defective from Lionel, it happens.  Make sure there is voltage on the smoke unit itself.

John what has been your experience with a defective AC regulator?

I recently had to get another two from Lionel due to one crapping out again, the engine also happens to be a TMCC J class (6-38095). I put a new regulator in the engine, an 8 ohm resistor in the smoke unit, and when power is applied to the track the regulator shorts. Checked all wires, connections are secure and not touching each other or metal.

My experience has been poor, but shorting out isn't normally a symptom.  The TMCC ones usually start losing control of smoke volume, then they won't control the smoke unit at all.  Sometimes they will start out full power and gradually reduce the smoke until there's no smoke.  Cycling them off/on returns the smoke to full power for a brief time.

@TheThirdRail91 posted:

@gunrunnerjohn Thank you very much for the info, i was hoping you might look at this haha. Just to clarify the supply in question should be .....

691REG5A00

DC REGULATOR BOARD / 5 VOLT

correct?

What is the 691REG5A00 DC REGULATOR BOARD / 5 VOLT used for??  Thanks, Pat B.

That has nothing to do with the smoke, that's a regulator module used to supply 5V when the small 5V power on the R2LC isn't sufficient.

@lpb007 posted:

What is the 691REG5A00 DC REGULATOR BOARD / 5 VOLT used for??  Thanks, Pat B.

Most likely for the three wire IR transmitter. The three wire transmitters have a transistor buffer on the board to reduce the load on serial data from the R2LC.

One benefit of this setup is if you ever replace the DCDS or DCDR motor driver with a Cruise M you won't have to worry about killing serial data when its wired to the Cruise M.

Pete

I am having the same exact problem with the same 6-38095 loco. I also replaced the resistor and am wondering if the cause of this problem was found?