Problem with LGB MFX 27-pin sound decoder

[NTJ]

Hi!
I have an LGB MFX 27-pin sound decoder where I can get everything to work except to drive. I can read all CVs and program it. Sound works and so do all function keys. If I set it to drive on DC it runs but it fails when I am trying to run it using DCC. I use a DCC-EX command station and JMRI. My other locomotives work but not this one. Can anyone help me find out what is wrong?
Peter

[ge_rik]

Hi Peter
Welcome to the forum.

This is what AI suggests. No idea if it's any help but I have enquired elsewhere and if I get any replies, I'll let you know

If your LGB MFX decoder works on DC but not on DCC, consider the following potential issues:

• Protocol Settings: Ensure that the decoder is set to recognize DCC. The default setting may prioritize MFX over DCC. You can change this by adjusting CV 50. Set CV 50 to 2 to disable MFX and allow DCC to take precedence.
• CV Configuration: Check the configuration values (CVs) related to driving functions. Ensure that the relevant CVs for speed and direction are correctly set.

Steps to Diagnose the Problem

• Check CV 50: Confirm that CV 50 is set to 2 to disable MFX.
• Test Other CVs: Review other CVs that control motor functions. Make sure they are set correctly for DCC operation.
• Power Supply: Verify that your DCC command station is providing adequate power. Sometimes, insufficient power can cause issues with specific decoders.
• Decoder Reset: If problems persist, consider resetting the decoder to factory settings. This can sometimes resolve configuration issues.

Additional Considerations

• Compatibility: Ensure that your DCC-EX command station is fully compatible with the LGB MFX decoder. Some command stations may have limitations with certain decoder types.
• Consult Documentation: Refer to the decoder's manual for specific CV settings and troubleshooting tips.

If these steps do not resolve the issue, further assistance from a specialized forum or a technician familiar with LGB decoders may be necessary.

Rik

[ge_rik]

This is what PhilP, also of this parish, posted in response to me repeating your enquiry on the GScale Central forum

My first guess would be speed-steps? - Check CV 29.
Both decoder and configuration in Central Station have to match.

Also, long-address or short-address. - Although if the sounds can be controlled, I think not?

Do DCC-EX / JMRI support MFX? - If not turn it off in (from memory) CV 50.

I am sure others will make suggestions, as well.

PhilP.

Looks like CV 50 is a common thread.

Rik

[ge_rik]

Another response on GScale Central

Indeed, CV50 bit 3 mfx aus/ein can be set to off. Sometimes the decoder has problems deciding which protocoll is used, analog, dcc or mfx. Lift the loco on and off the track several times so the dekoder will reset itself searching for the right protocol. I found after programming with DCC the loco will not be recognized by the Central or Mobile station at first on mfx, but then all the sound functions should not work either......

Rik

[NTJ]

Hi and thanks for all the advice. I believe I have tested them all but without success. The fact that I can program the loco and it "jerks" during the process make me believe that the decoder output is OK, together with the fact that I could set it to analog DC drive and drive it. When on main I can control light and sound functions which makes me believe the protocol is correct.
I will continue to test but so far no luck!

Regards
Peter
https://www.facebook.com/Mangskoggardenrailway/

[Palmerston]

have you thried to reset the decoder to factory setings via CV

[NTJ]

yes, tried that as well, thanks!

[Palmerston]

Can you run the loco on a friends layout using DCC?

Do you have another loco equiped with the same 27p decoder? or maybe a friend has. Does your friends loco (if any) run with your DCC equipment?

[Palmerston]

Do you have a friend which uses the same DCC equipment as yours?

Having owned 3 different DCC central stations i have learned that DCC is not as standard as expected. The track voltage needs to be at least 22V (digital e.i. power supply) Some central stations limit the voltage output to HO standards , no matter which power supply voltage.

[NTJ]

Monday I will bring it to test with an ECOS command station.

[NTJ]

Now I have gotten to a stage where I can get the motor to vibrate when I set speed on the throttle but it will not rotate.

[Palmerston]

Any progress?

[NTJ]

Hi!
Unfortunately no. I have not been able to test with any other CS and the decoder tester we have at the club is for ESU decoders. I have not given up though.

[Palmerston]

CV 2 to 5 and 52 to 56 are settings for the motor.

Is the decoder an empty one like LGB 55029?

The decoder probably does not use these settings for analog DC, so it does function there.

[NTJ]

There is no pn on it but I believe it is an older LGB55029, as they look the same. Reading the type from CV returns "LGB MFX 27-pin sound decoder"
As I bought it second hand I am trying to figure out if the previous owner has set any CV to a value that prevents it from working. Would be good to know what ALL CV's should be set to (all that possibly has anythiong with this to do). I use JMRI DecoderPro. It could be that the decoder is broken but as I can read and program the decoder, it at least able to control the outgoing current to return CV values. Could it br that the return current to send CV values is controlled by a different circuit than the motor H-bridge? All sound functions can be controlled. In positive direction the motor vibrates, in negative direction it is dead.

[NTJ]

I thought doing a reset in DecoderPro would do a full factory reset but no. When I set CV8 to ( the decoder works. At least the wheels are turning. Now I need to figure out which setting it is that prevents them from turning.
Thanks for all your inputs. I am sure I will be back with more problems or better, help someone with problems I have been able to solve.
My garden railway runs with a homebuilt DCC-EX command station amd JMRI to control it. To DCC-EX I have added WiFi controlled turnouts (an esp8266 and servo in each turnout) as well as my latest design, a two wing semaphore with an esp8266 and two servos. I share 3D designs and software for free if anyone is interested.

Peter

[Palmerston]

With an empty LGB 55029 the motorsettings can be done by auotune, software mDecodertool3 by Marklin.

Only the retrofit sounddecoder LGB 55029 can be fully programmed. The factory-installed decoders can only to a limited extent. They are locked. You can adjust the CV, but not all, and certainly not the sounds, only partially disable them. Even with a Marklin Central station 3 you can adjust to a limited extent. For 55029 you still need the Mdecodertool3 and/or a Marklin CS for sound. The advantage of this is that you do not need to know any CV and the so-called mapping is also very simple. Even though the decoders look the same at first glance, there are differences in electronics and programming options, the older have 16 functions and the newer 32. And indeed what I find annoying is that there is no indication at all, only a number that seems to come from the printed circuit board manufactor. The 27p connection is still the same. These decoders were originally developed by ESU. Unfortunately they don't have sound files for the locomotives I like. Massoth does, but their decoders are more than 10 years old and have no mapping, which is very useful, especially if you are already used to it. Their function decoders have more options as they are newer generation. Massoth eMotion XLSC has been announced for 2019, 7 years ago. The microcontroller used for these may no longer be available in a few years.

[NTJ]

Thanks for the info.
Luckily the sound in the decoder fits with the locomotive i am installing it in.

Peter