DCC Disaster.....?

[Patrick Davey]

So it was DCC day today and it started off well with a chipped A3r showing off a range of impressive lighting effects and sounds.

Then I decided to chip my MM 125 but I placed the loco onto the by now DCC-ed track before fitting the actual chip, there was a buzzing sound and she won't run, on either DCC or DC.  The chip is fine though, worked great in my other 121, No. 132.

I had been aware of the dangers of doing what I describe above, but perhaps the excitement made me fire ahead carelessly.

What have I done........?

 

[DJ Dangerous]

Somebody posted a similar question a year or two back. Wracking my brains trying to think who had a solution. Possibly @irishthump but don't hold me to that!

[Georgeconna]

How Long did you have it on the Track, I take it you had the blanking plate still in. 

Could you kaputted the motor. did this with a N gauge loco some time ago by accident, Had 2 of the same locos, the non DCC motor cooked up.

this DJ?

 

[Sean]

How long did you have the power applied patrick?

did you try to drive on the DC channel of your DCC controller, and what controller is it?

the buzzing sound would be considered "normal" as it is the motor taking the full voltage of your dcc system but not moving until the dc channel lets it move. since the motors arent moving they heat up to dissapate the power and this is why failure is common when people do this as motors overheat easily.

[Patrick Davey]

Thanks all - it was only on the track for a few seconds, I heard the buzz and took it off quickly.

It's an NCE PowerCab, how do I try it on the DC channel?  Do I need the DC controller connected for that?

Thanks for the help.

[Georgeconna]

The DC channel I think is number 0. Not a DC controller.

 

Your saying it aint moving under DC either so something has gone kaput, either the motor or PCB, any Smell of Burn off it when you take the bonnet off?

 

[Tullygrainey]

I need to step in here and take joint responsibility. I was present at the scene of the crime and party to it. I let him do it. Neither of us was concentrating properly - kids in a toyshop syndrome, I'm afraid.

As Patrick says, it was on the DCC powered track for 3 or 4 seconds. It still had its blanking plate in. When we subsequently inserted the chip and tried to initialise it and give it an address, the NCE system couldn't make contact with the chip and generated an error message.That suggests to me that something in the loco's circuitry has been damaged. No obvious visible damage and no smoke or burning smell.

Alan

Edited July 19, 2023 by Tullygrainey

[Noel]

Only a few seconds should not have damaged the DC motor when fed with DCC AC wave form. I’ve done it a few times myself by accident. Suggest diagnosis steps:

1. Put 21 pin DC blanking plate back in the loco, disconnect the NCE from the track and try a DC controller to see if the un chipped loco still runs ok on DC.
2. Assuming it does run, then remove from track, disconnect DC controller, put 21pin decoder in loco, put loco on test track, go into programming mode on NCE Cab. See if decoder manufacturer ID  and model no are displayed. This tells if decoder is responding. If yes give it a DCC address and try it on DCC. 
3. if it doesn’t run in 1 above it sounds like the motor was damaged by AC current for too long. 
4. if after step 3 it won’t run on DCC that might be because the address on the decoder is wrong. A decoder reset CV8=8 will reset the decoder back to factory defaults and default address of 3.
5. caution: with NCE Power cab only put one loco at a time on the track when programming or you risk programming every loco on the layout, and loosing loco addresses already allocated. Only have the one loco to program have only that on the layout.

 

Hopefully it’s not damaged. 

Edited July 19, 2023 by Noel

[Patrick Davey]

Thanks everyone for your sympathy, and for that detailed troubleshooting advice Noel, I shall indeed follow that.

@Tullygrainey Alan you are very gracious, but the responsibility is fully mine, I was totally aware of the risks but thought it was only an issue if the throttle was on, lesson learnt!!!

[Tullygrainey]

Thanks for this Noel. However,

1.  With the blanking plate in, the loco doesn't run on DC. (We tried it on Patrick's other layout Brookhall Mill which is DC)

2. With the decoder in, the NCE system can't make contact with the decoder. I think this is a electronic problem with the loco's own circuitry rather than a burnt out motor.

We know the decoder is ok because it's now installed and working in another loco.

 

[irishthump]

1 hour ago, Tullygrainey said:

Thanks for this Noel. However,

1.  With the blanking plate in, the loco doesn't run on DC. (We tried it on Patrick's other layout Brookhall Mill which is DC)

2. With the decoder in, the NCE system can't make contact with the decoder. I think this is a electronic problem with the loco's own circuitry rather than a burnt out motor.

We know the decoder is ok because it's now installed and working in another loco.

 

My ears are burning......

It sounds like something in the PCB has gone kaput. The fact that you can't get the decoder to make contact with your controller would support that. If it was the motor you would still be able to communicate with the decoder be able to turn the lights on and off.  You can doublecheck the motor is ok by removing the shell and applying current directly to the motor contacts, if you can get at them. Long time since I took the shell off a 121 so I can't really remember the layout.  

4 hours ago, Georgeconna said:

The DC channel I think is number 0. Not a DC controller.

 

Your saying it aint moving under DC either so something has gone kaput, either the motor or PCB, any Smell of Burn off it when you take the bonnet off?

 

Yeah I'd strongly advise to not use the "DC option" that some DCC controllers have. It works by "stretching" the AC waveform of the DCC signal so it is not true DCC. It can fry motors very, very quickly. Older motors like the Lima and Hornby pancake and ringfield motors can go bang in the blink of an eye. Some modern motors can also be susceptible to damgage.

[Signal Post]

One other thing that you may wish to try is (with the blanking plate installed) place it on a DC layout (or rolling road) and bring up the power whilst checking the directional lights on the loco, they should be illuminated at a reasonably high power setting even if the motor has burned out, if they are not showing then the problem is likely to be in the circuitry or wiring of the loco (as @irishthump has mentioned above).

Might also be worth trying the blank plate from your other 121 (No. 132), this would rule damage to the original blank plate (which I understand was installed at the time of the incident) from being the problem, it's unlikely that it is a blank plate problem but for the sake of a few minutes work might be worth checking.

[Georgeconna]

Was it ever run beforehand? 

[Patrick Davey]

Good morning folks, I am very pleased to report that all is now well!  I was going to try some of the diagnostic suggestions which were kindly provided here, so I opened up the access hatch on top of the locomotive and noticed that the blanking plate was very loose, which probably explains why it wasn’t running, anyway it is now running perfectly on both DC and now DCC, with all lighting and sound functions working!!

I feel quite silly for wasting your time…..

[Signal Post]

Delighted to hear that you got it sorted.

[DJ Dangerous]

23 minutes ago, Patrick Davey said:

Good morning folks, I am very pleased to report that all is now well!  I was going to try some of the diagnostic suggestions which were kindly provided here, so I opened up the access hatch on top of the locomotive and noticed that the blanking plate was very loose, which probably explains why it wasn’t running, anyway it is now running perfectly on both DC and now DCC, with all lighting and sound functions working!!

I feel quite silly for wasting your time…..

So @Tullygrainey was on the money about the motor!

[Flying Snail]

40 minutes ago, Patrick Davey said:

I feel quite silly for wasting your time…..

Don't, we all been there - banging our head against a brick wall trying to solve something that's turned out to be relatively simple in the end.

If it wasn't for your question, the rest of us wouldn't have gotten such a great list of things to check for when something like that inevitably happens to someone else in future

[Broithe]

 

Edit - Blimey! Just realised that today is July 20th, the day of the landing - that must have been an omen...

Edited July 20, 2023 by Broithe

[Patrick Davey]

Bliss:

 

(Turn up your sound!) 

[skinner75]

18 minutes ago, Broithe said:

 

Edit - Blimey! Just realised that today is July 20th, the day of the landing - that must have been an omen...

I only watched this last night about the Apollo missions - some craic on Apollo 12!:

https://youtu.be/tX3tJb5WUjE

[Patrick Davey]

Can anybody confirm that the video above is playing?

[Broithe]

2 minutes ago, Patrick Davey said:

Can anybody confirm that the video above is playing?

I saw it - after I had downloaded it, though.

Worth the effort.

[Signal Post]

Yes your video above (125 and A3R) are playing perfectly. Enjoy the benefits of DCC, I personally think that DCC sound is great on shunting type layouts.

[Tullygrainey]

1 hour ago, Patrick Davey said:

Bliss:

 

(Turn up your sound!) 

Yay!! (Breathes sigh of relief) Great stuff Patrick. Enjoy! 

[Georgeconna]

Nice one. Simple as that eh.  If the motor buzzed the blanking plate was in correctly at first. So it was the 21 Pin Decoder not connecting and subsequently  the blanking plate was not connecting either correctly.

 

Edited July 20, 2023 by Georgeconna

[DJ Dangerous]

3 hours ago, Patrick Davey said:

Bliss:

 

(Turn up your sound!) 

 

Love it!

I've seen videos before where the loco revs up before moving off.

How do they do that?

Holding two buttons on the controller at once?

 

[Patrick Davey]

4 hours ago, DJ Dangerous said:

 

Love it!

I've seen videos before where the loco revs up before moving off.

How do they do that?

Holding two buttons on the controller at once?

 

Still exploring it myself!!

[irishthump]

6 hours ago, DJ Dangerous said:

 

Love it!

I've seen videos before where the loco revs up before moving off.

How do they do that?

Holding two buttons on the controller at once?

 

You can get that effect by either using the brake or Drive Hold feature.