Hi all, Wondering if any can help me with this loco rescue. It is #39572 that has befallen to the voltage issue that they are well known for. I am unable to obtain the mother board or of its sister #39573 with board No:606233.
I have had to order a new bogie so I can use a high propulsion motor.(Old bogie motor screws just do not line up.I am going to use an ESU M4 #62400 sound decoder. I have made up my own board to house the roof lighting two contact tabs. Now my issue is how to wire up the Led's front & rear & what resistors do you recommend & how many do I need? I really would have liked to just get another motherboard albeit for a model like #37575 but nobody has one. If someone has pictures of such a conversion it would be most appreciated. Like they say a picture speaks a thousand words. Attached is a picture of the loco's demise.

Hi Dave, PJ has linked the necessary diagrams for the decoder. He is correct, the M4 and standard V4 wire the same. I would use the 21 pin adapter board. It makes future decoder replacement much easier. You must use a dropping resistor to prevent damage to the LEDs. 1000 ohms to 2000 ohms will work. You do not need anything that can dissipate a lot of power. 1/8 watt is okay for a couple LEDs, at four or more I would uprate the resistor to 1/4 watt.

http://www.esu.eu/en/pro...nen/21mtc-adapter-board/

Hi Matt, If I went into Jaycar what exactly would I ask them for? This led front & rear has three wires each. ones I have at present are 1.2 KOHM for single LED & 1.0 KOHM for two LED'S in series. Can I use any of these & if so which?

Cheers

Dave...

Hello Dave

I only use ESU decoders to convert my Marklin locos to DCC. I always replace the light bulbs with LEDs, and use the 1/4 watt 1K ohm resistors from Jaycar which I wire into the blue common return wire of the decoder. The 1K ohm resistors you already have should be quite adequate for your purposes.

Geoff

If the blue wire is the positive (+) common for the two sets of LEDs, that is correct. Blue is common plus for ESU decoders, but head lights are white and taillights are yellow, so I can't say for sure with the grey/yellow colors you have listed in post 10.

Can you post pictures of the front and rear of the circuit board for the head/taillamps? You may have the power limiting resisitor needed biult into the circuit board.

If you are going to operate the interior lights on an aux output, run a separate blue wire with a power limiting (1.2K ohm) resisitor for that circuit. It is helpfull to isolate circuits where possible.

Perfect. I just wanted to see if they had incorporated a power limiting resistor in the circuit board. They have not. Your 1.2k ohm in series with the blue wire will work.

That is very bulky wire, is that M's wire?

Hello Dave

Yes, that's correct. You only need to place the resistor on the blue wire.

Geoff

Thanks GeoFF, I could only get 1/2 W, 1.2 K-ohm resistors but that should be ok. Now I have to think about selling 39572 front bogie with brand new C-Sine motor & board.
I am just wondering what they would fetch on E-bay? Other alternative is to just keep it as a spare as these are like hens teeth. What do you guys recon?

Dave...

Hey Chook, I know the company well & bought all my wire from them when they have stock, soldering Iron & heat shrink. Top guys there. You recon the 1/2 w 1.2 Kohm is not the way to go? Better to get the 1/4 W version. The Jaycar mob charged me .50c for a pack of 8. The bloke at Jaycar said to me that the only difference between the the 1/2 & 1/4 is that it just accepts a little more power. That little more power has got me thinking it might just lead to the destruction of the Led. Your opinion please.

Regards

Dave...

Hi Tom, many thanks for your input. With all the given facts what resistor with what values do you think I should install. One resistor on blue lead front, one for the rear & one for the dome?

Regards

Dave...

Hi Dave,

As you have the driver board and assuming it isn't cactus you can connect any decoder you want, ESU or Marklin.

You can find the relevant details/settings for driving a C-sine motor in the ESU decoder manual, I can dig them out for you if you want.

EDIT:
From the current ESU manual;

11.5. Settings for the C-Sinus motor
LokPilot decoders with the 21MTC interface can drive the new
C-Sinus motors indirectly via the circuit board installed in the locomotive.
The LokPilot can generate all necessary signals provided
you re-adjust certain settings:
Load compensation must be turned off as described in chapter
11.2.
The control electronics of the motor also need a switched logic
voltage provided by the LokPilot on output AUX4. AUX4 must
therefore be active while the locomotive is stopped and while it is
moving (in both directions!).
LokPilot V4.0 LokPilot V4.0 DCC LokPilot V4.0 M4
LokPilot micro V4.0 LokPilot micro V4.0 DCC
LokPilot XL V4.0
Write the values below into the respective CVs
Make sure that CV 31 contains the value 16 and CV 32 the value
2.
CV Value
CV 266 32
CV 282 32
CV 298 32
CV 314 32
Use the LokProgrammer alternatively in order to activate AUX4 for
the stationary locomotive and for the moving locomotive in both
directions as shown in figure 26.
Furthermore for certain models the serial interface (SUSI) must be
activated since the control electronics receive their commands via
this interface. Turn on SUSI by setting bit 3 in CV 124. Based on
the default value for CV 124 (20) you should now write 28 into
CV 124.
Unfortunately there is another hurdle to be taken: The C-Sinus
circuit board draws too much energy from the LokPilot decoder. If
you have activated RailCom or Märklin brake sections there may
be some erroneous behaviour. To rectify this connect a 470 μF
capacitor between U+ and the common of the decoder as shown
in chapter 6.10.2.

Hope this helps however I'm sure Tom or one of the other lads can provide far more detailed information if needed. I haven't had to do a replacement decoder for any of my C-sine/SDS motors yet so this is the limit of my knowledge.

OH, while I think of it.

As to the resistors, although the 1/4w ones will be more than adequate in most cases since we in general live in warmer climes I use 1/2w purely to avoid excess heat build up. The 1/4w can run hot if pushed and not ideal especially in plastic bodied loco's or if in contact with other components.

Its just me being over cautious and preferring to play it safe as the size difference/cost is negligible.

Hi!
I would expect that one of these cables connect to either AUX3 or AUX4 (function output without amplifier).
I'd expect two motor outputs, decoder plus, decoder minus, function output. I never investigated this, but Märklin is flexible with respect to cable colour schemes.

Maybe you can trace the pins on the 21MTC socket that connect to the five solder pads on the big board- even if you don't remember where each colour cable from the small board was connected.