Skip to main content

MTH  Railking  NW 2  switcher.  ps2  / 3 volt with BCR2   (  also used super caps with direct connect to board )

MTH  DCS  /  Z1000  / TIU WITH REMOTE USED........Perfect operation.

MTH  Z750 AND Z1000 CONTROLLER for conventional........using directional switch for forward and reverse and the engine goes onto shutdown and then restarts. ???

What's going on here???  🤤


Videos (1)
Original Post

Replies sorted oldest to newest

Stan , I'll give that a try.  Thanks.  (  I was going nuts trying to get the video done before the required 100 MBs Stan.  😓 )

John , I havent tried a battery in it in a long time. I have the correct Nicad and  a NiMH charged on the MTH charger.

The thing that I couldn't understand was that on DCS it comes up right away and everything works perfectly.   I usually wait until the idle settles down, usually in about 10 seconds or so.

I only have a RK USRA Mallet ( with GRJ's super cap ) and a RK Dash8 ( with a BCR2 ) in ps2 / 3volt trim that I tried this on and there wasn't  any issue like on the switcher.  All the ps3s steam or diesels that I've tried on this test loop so far were good also .

Can't  wait to try your suggestions guys.

Thanks 😉

Stan, I couldn't get anything different happening even waiting up to 3 minutes . Shut down power and waited a few minutes then dialed power up to what I think was about 3/4 power.    It started up and the idle settled down about 10 or 15 seconds but I waited again for 3 minutes before I pressed the direction button ........still just shut down and came back up in what I guess is neutral .  Repeat method again with same results. 🤔

John , attached the NI-MH . ( 2.495 volts ) .  Using the above method again for changing direction and the same results as before.🤔

I don't get it .   I would have thought there would have been the same kind of problem when using the DCS.   When I would run it after the initial start up and the idle settled down it would be ready to go.   It does the same as on the conventional track ,      idle sounds , cab chatter , horn , bell , engine sounds and lights .  Except on DCS  with the remote it does the direction change, speed change, etc., just like it is supposed to. !!!

It's a mystery.   Must be something simple.

The BCR or battery provides short-term (for seconds) power to the PS2-3V board when there is NO TRACK POWER.  In DCS-command mode you always have track power even when changing direction. OTOH in conventional mode you momentarily remove track power to signal direction change; and of course when you press the Direction button track power is momentarily lost...and the BCR (or battery) kicks in.

The battery circuit draws on a charged BCR or charged battery when track power is lost.  It converts the ~2.5V battery voltage to around 5V for use by the PS2 digital/audio electronics.  Since your sounds IMMEDIATELY cut out when pressing Direction, this tells me the converter circuit is broken.  One of the MTH Tech gurus can comment but I don't see this as a DIY repair job.  I suppose to satisfy one's curiosity you could look at the corner of the board where the 2-pin battery plugs into the so-called power-supply board of the board pair.  There are about a dozen components (top and bottom) around the connector that do the heavy lifting.  If you see a charred or obviously damaged component or can sniff the tell-tale burnt electronics in that corner of the board then at least you'll know it's not something "simple".

While the parts cost to repair the voltage converter circuit would be maybe $1-2, it's the component-level expertise/labor, shipping, etc. which might be a show-stopper.  At one point in time it seems you could replace the entire power supply board but even then I believe the board was something like $75 (?).   

As an aside, you may ponder whether you could simply run this engine as-is but only in DCS command-mode.  One not-so-obvious use of working BCR/battery power converter is for saving DCS parameters between operating sessions.  So if you need to change the DCS engine address, the change would NOT be saved thru a power cycle.  Same with changing volume settings, smoke settings, and so on.

Dan ,  I did the remote and then the conventional resets withe the same results .   I probably should just run the engine on DCS .  I guess I just want to get it to work like it should .  You know " curiosity  killed the ........"

Stan,   " to satisfy my curiosity " I'll have see what might be an obvious issue on the boards. 

John , I haven't put the shell back together after installing that battery last night so I'll try to look at the boards.

Thanks guys.🤗

In round numbers the battery circuit is within the circled red areas on top and bottom of the Power-Supply board.  You probably don't want to mess with separating the boards so you'll just have to see what you can see from whatever vantage point you can get.

Long-shot, but examine the battery connector for a "loose" solder joint which might actually qualify as a simple repair!

battery circuit ps2-3v


Images (1)
  • battery circuit ps2-3v

Well Stan,  I  seperated the top and bottom boards and found no evidence of any problems in the battery connector area.

I did find a suspicious component on the bottom of the lower board.  ( see photo ).       I soldered a new one from a donor board .  The wire going across the suspicious area was rubbed through the insulation but only enough to barely show a glint of shiny wire.    Don't know if there was any connection with the component in question.

Anyway nothing changed with the original operation ............however ....... I think the boards are toast.  🤔   I must have touched some wires together that must have caused a problem.     Something I have never seen on my other proto 2 /3volt engines wiring.

The red and black wires from the trucks , the two entwined speaker wires and the yellow and white entwined wires to the motors all had about five mm lengthwise open slits in different places on the insulation ,down to bare wires.  I must have touched them together when putting the boards and connectors back together.

Anyway before putting the shell back on ,I ran it on DCS this time .      I had forward and reverse lights , no sound and using the remote at 1 or 2  SMPH the engine would start out slow and gain speed, probably to 100 SMPH !😨.     I was able to do startup and shutdown intermittently only.   

So I suppose there isn't much use in further work without getting into a very large cash outlay ! 😕

Gotta thank you for your input Stan. 🤗


Images (3)
  • 20210309_112630~2: Bottom of bottom board
  • IMG_20210311_114906255: Bottom of battery power port
  • IMG_20210311_120926550: Top of battery power port.

Well that was not a story with a happy ending.

Those multiple 5mm exposed slits in the wiring is suspicious suggesting this engine was an accident waiting to happen...and wouldn't you know it, it happened!

If the component you changed was the one above the black wire in your photo, that drives the smoke heater so I would not expect it to have changed anything wrt the battery/BCR operation.

No sound on a PS2-3V is typically a blown audio amp IC on the lower/larger so-called Processor Board which is a tedious soldering job of a $3 chip.  The audio IC has been known to blow if you indeed have exposed speaker wiring. There have been many threads on this.  Loss of speed control following the fondling of the wiring harnesses could be a loose/shorted strand of wire in the 3-wire blue-gray-orange tach wire set where soldered to the tach board on the motor.

I'm thinking this is a lost-cause... just my opinion of course.  After all, something caused the battery/BCR circuit which started this trip down the proverbial rabbit-hole.

Actually, in the lemon-lemonade category I wonder if there is any "scrap value" to a PS2-3V board that exhibits your board's behavior.  Since it appears the PS2-3V Processor Board is no longer available, and it does seem to do some things, I wonder if there's some salvage value to the right person.

Thanks for your help Stan.  👨‍🎓

I had to put the switcher aside for awhile. 😩

I've run 7 engines on this same conventional O27 test track performing normal maintenance while I was at it  .      1 was a ps2 /3volt USRA 2-8-8-2 and 6 were ps3 steamers and diesels.  I had perfect results from all of them.🤔

Sometimes you have a good day........                                 of the steamers  (  RK  Pennsy  tuscan color ps3 4-6-2  )  had no marker lights , no fire box glow and from when it was new always had somewhat kind of a scratchy sound to I had to get back to work?.................marker lights connector wasn't tight , wire and bulb replaced with a new wired bulb and replaced the 4ohm 4watt speaker with a known good one .    Everything came out well.    It was a good Saturday. 🙄

Add Reply

OGR Publishing, Inc., 1310 Eastside Centre Ct, Suite 6, Mountain Home, AR 72653
Link copied to your clipboard.