Large Scale Central

LGB Mikado 23872 Wiring

I’m installing a Zimo 699LS decoder in my LGB UP Mikado 23872. Anyone who has done this before, do you have the pinout for the 26pin ribbon cable? I really don’t want to have to completely take this engine apart if I don’t have to.

I do not have any info on that cable and when I install decoders in engines I remove original electronics and wire up the decoder directly to everything.

On the email question here is my answer for all:

  1. Zimo projects typically wire up the sound on-off to F8 and smoke to F6.
    Which firebox, bulb or led? I ask as the bulb version needs an inrush resistor for the high startup current.

  2. I wire all 5 volt functions to 10 volts as LGB uses 6.2 to 6.8 volts for lights and smoke units. Set CV 114 to 128 to get 10 volts to smoke unit, and set CV 60 to 160 to limit voltage to all other connections.

  3. CV114 to 128, CV132 to 72, and cv137 is low heat, start with 75, cv 138 med heat set cv 138 to 100, and cv139 for high heat (Accelerating) with 130. IF smoke is too low, be sure you did a 20 second warm up and then adjust the cv’s a little higher one by one.

Note to make all lights turn on I do the following
I set CV127, 128 to 0 and then program CV33 to 13 and cv 34 to 14. I tie cab light to F1 and firebox to F2. NOw F1 and F2 are only for sounds as F0 and direction control the front/rear/cab/firebox lights.
And if marker lights, then I have to add F3 for the markers and set CVC 33 to 29 and cv 34 to 30.

Thank you. Didn’t realize you set all your engines to 10v. Makes sense as it keeps things simple and to a standard.

Guess I am going to have to take this thing all the way apart. Shame as it would be sooo much easier to just tie into that ribbon cable.

No marker lamps, though they would be cool. Does anyone sell these ready made with the bulbs and wire?

The firebox bulbs are LEDs and are the original bulbs. Only ones on this engine which are LEDs. Probably since they are such a PITA to get to.

The firebox lamps are supposed to flicker. Will tying them to the other lamps still enable them to flicker?

OK, I have the wiring all sorted except for the bell/whistle/chuff sensors wiring. There are two connectors. I assume the left one is for Bell and Chuff while the right is for Whistle. But I am unsure about which wires are for pos and negative. I think the 3rd wire from the left is the chuff sensor. But not sure about wires 1 and 2 and 4 and 5 as the traces on the board go too far down past the axle/gears to see. I don’t want to disassemble the motor blocks. Does it matter if I get the pos and neg backwards for the reed switches?

Not good to reverse the polarity as most LGB engines now have hall effect sensors instead of reed sensors, esp on the circuit board with 3 identical hall sensors. Of course glass reeds do not care and the common for Zimo decoders for bell and whistle is ground. I have always used the BEMF for chuff. LGB had a psuedo standard where the center wire was brown for the bell/whistle common ground in engines.

So trial and error is not an option here.

All 5 wires are black. The leftmost wire is connected to two pins on the ribbon cable. I would think this is a common. If so, wire 2 should then be the bell.

As per our other conversation, I think I have the old version of the drive shaft. It is steel or aluminum with a round black sleeve behind the sensor. If it fails, can it be replaced with the beefier brass version?

Here is a pic of the Hall Effect Sensor Board in my Mikado. This one does not use the 4th lug from the left. There appears to be at least one other version of this board which actually uses the 4th lug.

Using two magnifying glasses and a bright light at just the right angle, I was able to see some numbers etched into the Chuff sensor. S??451. I could not find any references to the 2SSM130s at the bottom. Honeywell makes a SS451A HE sensor so I went with the info on its data sheet. It says that the left leg is +5v, middle ground and right leg is signal output. The SM130s seem to have a different leg configuration, which was what was confusing me since I was told they are a HE sensor.

Following the traces and the S451 data sheet, I determined the board’s lugs are from left to right

1= Ground, 2= Bell signal IN1, 3=Chuff signal IN3, 4=Not used, 5=Whistle signal IN2, 6=+5v

If I am incorrect and I release the magic smoke, I will update this post. But I have enough info to place this bet.

The old Mikado drive system has 1 small ball bearing on end drive shaft.

The new system has 2 larger ball bearings on these shafts so the motor block (top plate is different!!) must be swapped out as well as the motor and 3 drive shafts.

Also motor has a solid brass fitting that engages a matching plastic cup and the drive shafts now have a square end so the plastic cups no longer slip.

The motor has a brass gear on the end. There is one bearing in the rear wheel section. I didn’t remove the plate to the front wheel section though to see if there was a bearing in there.

The chuff sensor is working correctly but the Bell and Whistle are not. I set the decoder CV268 to 1 to use the chuff sensor as opposed to the digital chuff and it works, disconnected the 5v and the chuff stopped, so I know that is working fine. I am told the digital chuff is better so I set the CV back to 0. But I still want to use the track sensors.

I hooked up a mogul sound function trigger to IN1 and IN2 and still get nothing. I am told there likely aren’t any sounds allocated to the IN1 and IN2. I have downloaded JMRI and am waiting for the cable so I can allocate the sounds to CV300 = 111 and 112. I can’t figure out how to do it with my ProCab.

FYI The LGB standard is bell on left rail and whistle/horn on right rail.