MTH 20-3029-1, converted to PS2, no sound/smoke

My guess is the previous owner had the conversion made with strictly DCS-command operation in mind.  Perhaps it was extra "work" to install the smoke on/off switch and the volume control potentiometer.

If you are able to open the tender where the PS2 electronics boards are more than likely installed, you might find the wires to the smoke switch and volume control are just dangling/disconnected.  In any case, the components/wires to control the smoke and volume for conventional operation are, say, $5 or so.  If you're not a DIY'er, you'll pay much more for labor/shipping to install and wire-up the switch and potentiometer.  If you are a DIY'er, there are many diagrams and photos showing exactly what you need to do...for example the instructions for the albeit no-longer-available PS2 upgrade kit.

So sans the volume potentiometer and smoke unit switch those items will not function in conventional operation? If so do you have any links to the items I would need? I can pop the shell off the tender tomorrow and take a picture if it helps.

For conventional operation you need the volume pot and the switch to control the functions.  Without the parts you can arrange the wiring so that the volume is always full-on (or full-off) and the smoke always ON (or OFF)...in other words no control but the functionality is there.

Take a look at the PS2 Steam upgrade manual.   Some relevant pics copied here:

There is a 12-pin connector on the electronics board with wires that go to the volume pot and smoke switch.  Since the kit comes with these wires, it's hard to imagine why they would have been removed.  I understand them not being connected (if conventional mode was not needed) but I'd think they might be there.

The parts list for the 20-3029-1 shows the volume pot and a switch in the tender with cut-outs on the bottom to access the controls.  The volume pot (item 19) has a unique plastic holder (item 20) which aligns with the mounting holes.  It's curious someone would remove these parts; sure, leave them disconnected if not needed but why remove them!

If for whatever reason these parts are indeed AWOL, the parts list gives the MTH item numbers down to the last screw, washer, etc.  I suppose you could use a generic volume pot of the right value and a random on/off switch...but the cutouts on the floor of the tender exactly fit the MTH parts simplifying installation/mounting.

I found the instructions for the PS2 upgrade. I'm going to pop the tender shell and see if the wires are there. If so I'll connect them. If everything works I'll order the volume potentiometer and switch for the smoke unit. My guess is since the locomotive was run/setup for DCS use these items were not connected, especially since the locomotive moves/lights up under conventional operation.

stan2004 posted:

For conventional operation you need the volume pot and the switch to control the functions.  Without the parts you can arrange the wiring so that the volume is always full-on (or full-off) and the smoke always ON (or OFF)...in other words no control but the functionality is there.

Take a look at the PS2 Steam upgrade manual.   Some relevant pics copied here:

There is a 12-pin connector on the electronics board with wires that go to the volume pot and smoke switch.  Since the kit comes with these wires, it's hard to imagine why they would have been removed.  I understand them not being connected (if conventional mode was not needed) but I'd think they might be there.

 

The parts list for the 20-3029-1 shows the volume pot and a switch in the tender with cut-outs on the bottom to access the controls.  The volume pot (item 19) has a unique plastic holder (item 20) which aligns with the mounting holes.  It's curious someone would remove these parts; sure, leave them disconnected if not needed but why remove them!

If for whatever reason these parts are indeed AWOL, the parts list gives the MTH item numbers down to the last screw, washer, etc.  I suppose you could use a generic volume pot of the right value and a random on/off switch...but the cutouts on the floor of the tender exactly fit the MTH parts simplifying installation/mounting.

Not having the wires hooked up for conventional control of the sound/smoke unit was the issue. Thanks! The wires were tied off to the side in the tender. I temporarily hooked the wires together and everything works fine. I'll be buying the volume pot and smoke unit switch from MTH shortly.

So MTH no longer sells the volume potentiometer. I have a couple 10K ohm linear potentiometers siting around. Would one of them work with the 3 volt PS2 system in my GS4?

Any 10K pot will work.

Lou, The GS4 is looking, sounding, smoking good now with the wires jumped together.

This is an excellent lesson for any DCS operator who performs upgrades like me.  Who knows when I may sell, or upon my passing, my wife may sell one of my upgrades to a conventional operator.  Always include the switches and potentiometers!!  

stan2004 posted:

Any 10K pot will work.

Thanks for confirming. I'll hopefully get around to installing it in the next few days.

Mark Boyce posted:

Lou, The GS4 is looking, sounding, smoking good now with the wires jumped together.

This is an excellent lesson for any DCS operator who performs upgrades like me.  Who knows when I may sell, or upon my passing, my wife may sell one of my upgrades to a conventional operator.  Always include the switches and potentiometers!!  

That or leave the wires tied off to the side and a note with instructions in the box.

But that only works for people like me who aren't afraid to take things apart and solder. 

That's right Lou!!  Better to do a complete job, so it doesn't matter who gets it in the future.  At least that's the way I look at it having worked in electronics for 42 years.  However, I know plenty of "professionals" who look at it the other way; let the next guy worry about it!