MM121 POWER CUT OUT ISSUES

[johnfromoz]

Hi all, have about fifteen Murphy locos, B121 being the first time I've encountered any DCC issues. Long story short, loco cuts out dead on my Powercab at anything above speed step 40. Lift it off track, replace on track it will run again, but only to speed step 40. Try to go higher results in it stopping 10-20 sec later.    Tried 3  decoders, incl MM sound chip, same result with all, so it's obviously a heat/ power issue on the loco circuit board somewhere, no obvious signs of burning/ heat.

I may have to consign B121 to yard shunter duties as a scale 40kph is no suitable for main line running....

Any ideas DCCers?

John

[NIRCLASS80]

ESU sound decoders can have a current overload set to operate. I would remove the decoder, refit the blanking plate and try on standard DC. See if the motor runs hot or if the loco runs significantly slower than you would expect. It sounds more like a faulty motor than anything else. 

[leslie10646]

Amazing that this should have cropped up today. My 121 won't move at all, after an attempt to program it to its running number (tried both "21" and "121") -

I had been running B121 as "03", so tried reprogramming it (on my Digitrax set-up) to "121" - the address appears to have been written OK, but after putting it back on main line - one dead loco.

By the way, tried programming it on both my "Zephyr" and the radio-equipped hand-held job - both times with loco on a Porgramming track as we are told to.

More than one person on this forum said they wouldn't touch Digital with a barge-pole - maybe they're right?

It's been one of this days - I won't bore you further.........

(Signed) Haggard Pensioner, Frimley, Surrey

[johnfromoz]

Hi Leslie, haven't got to address issues yet, but mine definitely has a circuit board fault somewhere, causing a short above certain  power levels or heat thresholds. I have been over the board with a magnifying glass looking for stray solder tracks and have cleaned it up a bit but problem persists. Loath to send it back to Kernows from Oz.

Have you reset your chip? ( IE 8 to

John

[Noel]

6 hours ago, johnfromoz said:

Hi Leslie, haven't got to address issues yet, but mine definitely has a circuit board fault somewhere, causing a short above certain  power levels or heat thresholds. I have been over the board with a magnifying glass looking for stray solder tracks and have cleaned it up a bit but problem persists. Loath to send it back to Kernows from Oz.

Have you reset your chip? ( IE 8 to

John

Suggest send it direct to Murphy models under warranty. I got great service and a replacement direct from MM within 48hrs. A middle man just adds delay and unnecessary pain. MM warranty service is excellent.

PS on addressing note programming 121 as a loco address is treated as a long address by some DCC controllers and a short address (ie <128) on othe DCC systems due NMRA ambiguity. For example program 121 into a loco on NCE is not addressable by say a Z21 or Lenz and visa versa. As recommended above to mechanically diagnose a loco try on DC first with the DC blanking plate to illuminate all possible DCC causes.

[johnfromoz]

1 hour ago, Noel said:

Suggest send it direct to Murphy models under warranty. I got great service and a replacement direct from MM within 48hrs. A middle man just adds delay and unnecessary pain. MM warranty service is excellent.

PS on addressing note programming 121 as a loco address is treated as a long address by some DCC controllers and a short address (ie <128) on othe DCC systems due NMRA ambiguity. For example program 121 into a loco on NCE is not addressable by say a Z21 or Lenz and visa versa. As recommended above to mechanically diagnose a loco try on DC first with the DC blanking plate to illuminate all possible DCC causes.

Do you have a service email for Murphy Models Noel?

[Noel]

3 hours ago, johnfromoz said:

Do you have a service email for Murphy Models Noel?

Sent email via PM to avoid spam harvester if posted here on an open forum.

http://www.murphymodels.com/Aboutus.html

[leslie10646]

On 28/12/2021 at 8:21 AM, Noel said:

 

PS on addressing note programming 121 as a loco address is treated as a long address by some DCC controllers and a short address (ie <128) on othe DCC systems due NMRA ambiguity. For example program 121 into a loco on NCE is not addressable by say a Z21 or Lenz and visa versa. As recommended above to mechanically diagnose a loco try on DC first with the DC blanking plate to illuminate all possible DCC causes.

Hi Noel

Yes, I HAD read that far in the manual - the Digitrax programming feature offers FOUR different programming systems - had anyone on the forum tried changing the Loco address on a Sound chipped 121 - USING A DIGITRAX CONTROLLER? Mine's a Zephyr, with the option to use a Duplex handheld one - just to make it simple the job is done differently on each of the two!

Still got a dead 121. The shed pilot has been busy rescuing it!

[leslie10646]

God Bless Lord White (aka Old Blarney), who patiently (on the phone) talked me through resetting the offending loco, getting it to run again and finally give it the address I wanted.

All I've got to do now is clean the wheels and The CIE Enterprise can run again!

Well done, David, I owe you a pint!

[Old Blarney]

It was my pleasure.  It is good to know a 121 will be running through Portadown again.  Reality in miniature.

White.  

[irishthump]

14 minutes ago, Old Blarney said:

It was my pleasure.  It is good to know a 121 will be running through Portadown again.  Reality in miniature.

White.  

Great news. Nothing more frustrating than having a new loco act up!

What exactly was the issue?

[Old Blarney]

Good evening irishthump,

 

To answer your question.

The faulty Locomotive was not responding to any commands.

We have identical units to control our Model Railways -Digitrax. 

We synchronised our handset settings,

Reset the Decoder to Factory Default - 08=08

Entered the desired Locomotive address.

The problem (The faulty Locomotive was not responding to any commands) may have been that the desired two digit address (121) had been set as a four digit address.

I hope this is of help. If not, please contact me through this forum or, by a Private Message..

 

 

 

[irishthump]

4 minutes ago, Old Blarney said:

Good evening irishthump,

 

To answer your question.

The faulty Locomotive was not responding to any commands.

We have identical units to control our Model Railways -Digitrax. 

We synchronised our handset settings,

Reset the Decoder to Factory Default - 08=08

Entered the desired Locomotive address.

The problem (The faulty Locomotive was not responding to any commands) may have been that the desired two digit address (121) had been set as a four digit address.

I hope this is of help. If not, please contact me through this forum or, by a Private Message..

 

 

 

Thanks for the reply, Blarney.

I dont use Digitrax myself but I've heard of that issue affecting some brands of controller.

[johnfromoz]

Happy to report resolution to this issue of MM 121 cutting out around s/step 40.  Loco was returned to Kernows, who spent some time (amazing in itself!) recreating the problem and diagnosing a faulty pcb, before thoroughly testing a replacement 121 for an hours running to ensure it was fine.   That is what I call excellent support and service in this day and age.  That Kernows are still capable of investing time in customer support is a tribute to them.   The other big two in the UK could learn something from this…..

John

[johnfromoz]

So the replacement class 121 arrived here in Tasmania, perfect in every way.  Big note of thanks to Kernow Model Centre of Cornwall, UK for rare, personalised, backup service.  This was an obscure DCC fault that they took the trouble to investigate.  Cannot recommend them enough.