Help Required Please - Hornby B12/3 cutting Out

[Steve51769 38]

Has anyone else had a problem with their new version Hornby B12/3 cutting out? It will run for a short while then stall. If I leave it with no power for a few seconds and it will move again when power applied, the longer you leave it the longer it runs for. It's not the controller (H&M Duette) as a second loco on the same circuit continues to move even when the B12 has stalled. I've checked the tender feed, by swapping it for the one on my D16, the D16 runs okay with the B12 tender, and the B12 still stalls with the D16 tender. Is there a thermal cutout on the loco? This problem started in the hot weather last week so I did wonder if it’s heat releated, though the weather is cooler this week. Any suggestions/help gratefully received.      

 

Thanks

 

Steve

[34theletterbetweenB&D 12,087]

Does suggest heat build up as a possible cause of the cut out, but I haven't recognised any component to cause thermal cut out on mine.

 

Might be heating on the motor leading to a motor bearing or a brush seizing, when it cools function is restored.

 

Worth contacting Hornby service with this question I feel. I don't recall much in the way of trouble reported on this model, now going to find the main thread.

[34theletterbetweenB&D 12,087]

Seen a reference in the B12 thread to flywheels mounted too close to the motor, and binding, so that's one potential problem to look at.

[MikeParkin65 1,271]

Does the motor ‘hum’ when it stalls? That would suggest something binding. If it doesn’t it seems more likely there is a pickup issue with the loco. I’d start with the basics though, clean the wheels, inspect the pickups and look for any damage to the very thin and delicate plug wires.

 

If it’s new though there remains the possibility of returning it to the dealer of course. 

[Steve51769 38]

Thanks for the replies. It doesn’t hum when it stalls it’s dead. I saw the reference to the flywheel and wondered if that was the cause. As I mentioned I’ve tried swapping the tenders with the D16 (as current collection it through the tender not loco) and it makes no difference. All wheels are clean as new. I think I need to strip the loco down and check all connections with a multimeter. I was hoping that this was an easy fix.

 

regards

 

Steve

[Nimbus 354]

Do you have an ammeter to establish whether the motor is still conducting whilst cut-out?

 

The Nim.

[Fireline 208]

Sounds like the capacitor failing,

[Steve51769 38]

Update - I’ve stripped it down. Plenty of room between can motor and flywheels. Tried disconnecting the capacitor but it makes no difference. Motor runs then stalls even when run out of frames. Since testing it out of the frames it’s got worse. Conclusion is that it’s the motor failing. So now on the lookout for new motor unit. Any ideas where I can get one from?

 

regards

 

Steve

 

[MikeParkin65 1,271]

5 minutes ago, Steve51769 said:

Update - I’ve stripped it down. Plenty of room between can motor and flywheels. Tried disconnecting the capacitor but it makes no difference. Motor runs then stalls even when run out of frames. Since testing it out of the frames it’s got worse. Conclusion is that it’s the motor failing. So now on the lookout for new motor unit. Any ideas where I can get one from?

 

regards

 

Steve

 

Try soldering the motor to a separate power supply (ie totally independent of the B12). Optimist that I am I still think its a pick up issue - maybe I am lucky but I have yet to encounter a duff Hornby motor in 20 years collecting and far too many loco's bought 

[Steve51769 38]

OThank you Mike, You got me to investigate further. You are correct the motor runs fine when power is applied direct to it. This would point to a wiring fault. As the tender works fine with the D16 I will assume it’s the loom on the loco at fault. I’ve looked up the part on the Hornby service sheet (X6113) and checked Peters Spares site where sadly it is listed as out of stock. Any ideas if anyone else would stock/sell these? (Update found a source of equivalents on Ebay for £1 each).

 

At least it is a step forward.

 

regards

 

Steve

Edited July 1, 2020 by Steve51769
Update

[Steve51769 38]

I thought I'd add a postscript to this saga. Having ordered and fitted the new wiring loom for the loco it didn't fixed the issue. Using a multimeter I worked my way carefully through the wiring on the tender and discovered a dry joint in the PCB for the decoder. I resoldered the errant joint and tried the loco - in fifty years of modelling I've never seen flames from a loco as the joint on the opposing polarity decided that it too had had enough and started to burn. After extinguising the flame (fortunately no damage done) I resoldered that joint too and the loco now runs like new. To my mind Hornby need to beef up some of the wiring and soldering in these models as in this loco it was decidely poor. The loco could have caught fire in the normal course of running - not something that I would wish on anyone.      

 

Regards

 

Steve

[SweenyTod1 121]

I had a similar issue with my B12, but didn't comment earlier as the posts suggested the fault was at the loco end. I also found the fault in the  DCC socket/blanking plug. With some power on the track I was testing  with a multi meter and suddenly the loco leapt forward. I suppose I could have  resoldered as you did, but as I don't do DCC, I bypassed the  socket/blank and rejoined the pairs of wires in the tender. Now it runs happily, I'm pleased to say, Though I still don't know exactly whether the fault was in the blank, socket or both, it matters not for me. Glad you have a happy running loco now.

 

Tod