Lgb 21755 dcc issues

a98087

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Hi All

I have in my possession a brand new Lgb 21755 e10 loco supposedly with dcc sound fitted.

However when tested on dc and dcc, the sound doesn’t work.

The dcc system-was a nce pro cab, and the loco has a factory fitted sound decoder.

The loco was bought new, on first release a few years , and the is the first time it’s been tested.

We did a factory reset, and can read and write to the chip.

The motor and directional front lights work,

Any help is greatly received BA0DCCBB-5E33-4508-B65E-50BCADDAECD1.jpeg

Dan 62B97ECF-976F-40D0-A740-EDAC7AB4F0D4.jpeg
 

PhilP

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Did it come with an instruction sheet? - This will normally list the function key settings.

Early MFX equipped loco's had sound turned off on analogue (DC) power.
There may also be a volume pot. secreted somewhere?

F8, F5, and F6, would be my first function keys to try?
You could also interrogate the decoder, to find its model number, perhaps?
 

wandgrudd

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Sound on with F8 sound starts with F6, and if it’s the same as mine (which is a first issue) it has a volume pot but its hidden inside which stupidly is only accessible by taking it apart 10 screws on the underside (or adjusting CV-63 its set to full volume on first run “bit 255” I have mine on “bit 175”)
 

a98087

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Here’s the Manuel, in case anyone else has there problem,

But will test in the text few days, hopefully the experts here will have cracked it :) C091594E-D10A-4F84-84B5-391B29897915.jpeg
 

phils2um

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I agree with wandgrudd that you need to check the vol. pot is not turned all the way down. While you're in there make sure the speaker is plugged in too.
 

a98087

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Thanks for the advice, before i open the loco up to check, which is do you turn the pot for the volume? Does clockwise or anti-clockwise make it louder?

Dan
 

PhilP

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Thanks for the advice, before i open the loco up to check, which is do you turn the pot for the volume? Does clockwise or anti-clockwise make it louder?

Dan
The answer to that, tends to be 'yes'...
Quite often, you have to turn it the opposite way to the volume control on your radio. But, not always... :(

Setting it half way, you should definitely hear 'something' if the sound is 'on'.

PhilP
 

Dan

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If you are not using MFX then turn it off by writing CV 50 to 2. This makes the loco DC and DCC only and no MFX.
 

LGB333

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Actually, every LGB mfx/dcc/dc sound decoder I've set to CV50=2, it then reads "3." The locomotive user guides show for CV50 that Analog DC ON is 2, so 3 must be DCC and Analog DC ON. But regardless, mfx is turned off with 2 or 3. Marklin makes their mfx/dcc decoders to be prioritized on mfx operation, then dcc next priority, and finally dc analog. So, I've found these decoders to be touchy when trying to set CVs using dcc instead of mfx. Another point is that to activate the sound in dcc, you need to first press F6 Operating Sounds and then press F8 Sound On Off.
 

PhilP

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It may not be 'right' but that is what (certainly the early ones) did..

Another problem, was these were being supplied pre-installed in 'LGB' loco's, where previously, even the pre-installed electronics, was manufactured by Massoth.
People were so used to using their Massoth systems to change things, they got caught-out.
The Massoth system had a 'change address' option, and this would allow you to set a short, or long, address without doing the math, and altering a bunch of CV's manually..
Problem was, you were doing this to a Marklin MFX decoder, and not a Massoth unit. The Massoth system attempted to change a series of CV values, and failed part-way through, hence came back with an 'error'..
Meant you had to set CV 1 (short address), CV's 17 & 18 (long address, having done the calculations) and adjust CV 29 to choose which address to use..

It was a bit of a pain, to start with, but once we had worked out what was going on, we were fine.

PhilP
 

PhilP

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Phil, so you could write decimal 2 ( 00000010 ) to CV 50 and read back decimal 3 ( 00000011 ) on this decoder... wow!

More curious than anything else... (or incredulous !)
Correct..

When first introduced, they caused a lot of consternation, amongst owners..

The perceived wisdom, was to initially run the loco on default address '3', before trying to do anything else.
Those most upset, had analogue layouts, as almost everything was turned 'off' under analogue control, by default.
 

LGB333

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So just to clarify things, as all this dcc stuff confuses me.

What Cv needs to be what value to enable the sounds on Dc?

Dan
Dan, you need to consult the LGB User Guide to verify the specific settings for your locomotive. Marklin changed some of the CVs in the newer locomotives from what was in the older mfx/dcc/dc Marklin sound decoder. For my LGB 28443 RhB 50th LGB Anniversary Electric Loco, the guide states CV29 Bit 2 Analog Off/On = 0/4; Default =6. And CV50 Alternative Formats Bit 1 Analog DC Off/On = 0/2 and Bit 3 mfx Off/On= 0/8; Default = 10.

Since the Marklin mfx/dcc decoders are designed with mfx as the highest priority operating mode, then dcc, followed by dc, they recommend to turn off the operating modes not used in order to prevent potential conflicts between the technologies. So, for most of us as DCC or DC users, then turning mfx off is CV50 = 3 (DCC and DC ON, mfx OFF). As I posted earlier, when you try to set CV50=2, it then reads "3" instead of "2". So, Marklin should update their user guides to show that you can't just set DC operating mode, both DCC and DC are ON with the CV50=3.
 

PhilP

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Errrr....
If Bit 1 is 0/2

Then Bit 0 is 0/1

PhilP
 

LGB333

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Okay, it's not listed in the LGB User Guide. I've read in some Marklin documentation that you can not set the decoder for DC operation alone (CV50=2), must be DCC and DC, CV50=3. I did set CV50=1 and it did operate in DCC power, thus Bit0=1 and Bit 1=2.
 
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Greg Elmassian

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Ouch, sounds like binary school.

Luckily I needed to learn this in college so it is second nature.... many people will start numbering bits from 1 to 8 as opposed to bits 0 to 7 (correct), I recommend that people use CV bit calculators if there is any chance of confusion...

Greg
 

JimmyB

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