Garden Railway Forum

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

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

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

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

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/

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

yes, tried that as well, thanks!

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?

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.

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