Proto 2 Smoke unit testing

yes   a used 9 volt battery with the unit unplugged from the board ps2! and apply the 9 volt battery to the smoke fan motor it should run if it does not fan motor is probably bad, you can see if the fan  motor turns freely with your fingers if it turn freely with your  finger then motor is bad. there only $6.00 plus shipping from mth! if fan works ok plug smoke unit back into ps2 board and turn smoke on you should feel or smell the resister getting hot, if not the resister could be bad or the  ps 2 board smoke control circuit could be a t fault! 2 wires connect to the fan motor and 2 wires connect to the resister heater. you can also disconnect the smoke unit and just check the resister and make sure it reads ohms and not open. should read about 8 ohms. the four pin connector just below the 12 pin connector four wires 2 wires feed the smoke heating element n the other 2 connect directly to the fan motor.

Alan

Alan! That’s terrific!!! Thanks, will do as you have suggested!

best, Joe 

The fan typically runs on 5V.  FWIW, IMO a 9V battery is a bad way to test them, many defective fan motors will run with that much voltage applied, but not when connected to the DCS board.  I test the fan motor with no more than around 2 VDC on a bench supply.  If it won't run on 2V, it's bad.  The smoke resistor can be tested with a multimeter, they should b around 8 ohms, +/- an ohm.

If the PS/2 board has a bad FET for the motor or heater, they can be repaired for a lot less than new boards.

Thanks GRJ!!! You always come through!!! Off hand which typical FET fails? I holding out for a bad fan or heater!

 Thanks,

Joe

If you short either the heater or fan power, typically the associated FET gets cooked.  In extreme cases, sometimes you lose a trace on the board.

The heater FET is Q13 - IRLL2705, and the motor is Q20 - FDN5630.

also your smoke unit could have a grounded heater element which would blow the FET ! if

you need a smoke fan motor part number is 

BE-0000041 I'll sell you one if you need one ok!

alan

Thanks guys!!! You’re the BEST!

-Joe

FET Alan, FET.  There's only one smoke heater FET.

Guys! As usual, I dive into the shallow end without checking for hazards!!! I removed my cab to prepare testing the smoke unit. Ooops!!! My stupidity ignored what I'm sure is a crucial fact to my problem! There's a "plug" with about 10 wires that terminates at the rear of the engine! Now with my head on straight, It looks like the smoke unit from the engine goes to the plug, which in turn would go to the "tender" or "B" car, WHICH I DO NOT HAVE!!! I'm now assuming the circuit is incomplete? I hope there's a way to bypass the need for the "B" car??? Else, I need to find a "B" unit???

Dummie Joe!

I truly don't understand what you have at this point.  If you have a smoke unit and the PS/2 board in the same chassis, the smoke unit doesn't need ANYTHING plugged into the tether to function.

I bought the F3 chassis from a reputable dealer, who I had dealt with many times before. A few years back, I had a Lionel F3 that I painted up in B&M colors. So the MTH cab switch plan was to have “sound & smoke”. The chassis has PS2 boards AND a smoke unit. The plug from the smoke unit, besides having the 4 wires to the plug, it ALSO has a green and a brown from the plug, to a connection, that would go to a “B” unit. I haven’t verified the smoke unit yet, because when I realized the green and brown went to the rear connector, I felt the circuit was open? To sum it up, my smoke has 6 wires at the plug, but just 4 terminals. Double green and browns. If the rear connector doesn’t matter, then it’s gotta be a FET. Sorry for the confusion and my wordy explanation!

joe

SLow down that train, your jumping to too many conclusions with no facts.

First, do you have a transformer with amp meter like Z-4000.  Second if your testing conventionally there is a smoke switch that must be on.  Blue and pink wire to smoke switch or adjustable pot.

4 pin connector for smoke but AA units and double smoke unit models do double up the control wires brown and green.  That is what you have.

SO is the switch on?  DO you get a jump in amps that indicate element getting power.  You can measure across element to see that you have 8 ohms.  Then look at fan to see if impeller spinning.

YOu can have burnt element, burnt wick, loose impeller, bad motor, broke wire all which will leave you with no smoke well before a bad fet.  Smoke element fet shorts are very rare.  Fan motor shorts more common, but they usually result in a board short also.

So look at the smoke unit more closely.  G

Problems solved! BUT, I have to indicate the solution!!! The smoke switch, I was totally aware of, and had tried switching the part on and off a few times! FYI, I actually have two Z4000, and one Z1000 on my layout! But I never paid attention to the AMP draw! Long story short, the smoke switch was OPEN in both positions!!! I changed the switch, now I’ve got smoke coming out my windows!!! LOL!!! I need to find the correct collector for the F3 cab, as mine is a Lionel, mounted to an MTH F3 chassis!!! Thanks for sticking with me on this project!!! There must be a part number for the smoke collector that diffuses from the actual smoke unit. Mainly because they probably used 2 exhaust ports? 
My best to all, especially G!!!

Joe

  Save a fet, ride a switch.  Glad it was simple.  G

I made the initial mistake of “assuming”, because the unit was NEW, that the switch was good!!! Oops, never assume anything! Can’t thank you enough for your input!

best

Joe