R3480 EWS Brahms Shorts my DCC

[Kiwi Frazer]

Hello Hopefully I can get some good help here.

I have a R3480 EWS Class 92 - on DC it zooms around the track and gives me no issues at all.

As soon as I put a chip in (any chip I have tried multiple chips and they work no issue on other lcos) my DCC system keeps rebooting.

There are 2 bogies  one with the motor on and one without.  If I have the non motored bogie on the track only - I can program the chip....  But as soon as the second bogie goes onto the track... then the DCC starts rebooting.

As the chip works without issue on other locos on the same track and it happens on NCE and Hornby Chips - it is not the chip that is at fault.

So is it the wiring on the bodie with the motor?

Hopefully someone has some good advice.

Thanks

[Chrissaf]

What brand / model of DCC controller? it is potentially important to know as the answer can give a clue.

 

For this next bit you need a multimeter that can read resistance or at the very least check for continuity. Not got a meter? this essential piece of test equipment can be purchased for less than £8 delivered via ebay.

 

With the decoder removed from the DCC socket and the socket empty [being a Hornby model I would expect this to be an 8 pin NEM652 socket]. Measure the resistance across Pins 1 & 8 and Pins 4 & 5 you should measure a complete 'open circuit' that is to say 'Infinity' resistance. If you get a very low resistance reading or a 'short circuit' on either pair of pins then that is a fault that could give the symptoms you have described. That is to say 'working absolutely fine' on DC [with the DC blanking plate 'DC Bypass Plug' fitted instead of a decoder], but not working on DCC with a decoder fitted.

 

If you do see a low resistance reading, particularly if you see a 'short circuit' look at the underside of the socket with a magnifying glass to see if you can see a sliver of solder bridging the specified pins or wires to those pins bared and touching.

 

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If my suspicions are correct and this wiring fault is present, then your controller constantly re-booting is likely protecting your decoder from being permanently damaged.

 

The above is a fairly commonly reported wiring fault. However, given your description about what happens with regard the two bogies, your wiring fault might be a different one and a little bit more obscure.

 

It may also be a motor fault and not a wiring fault at all. So tell us the resistance reading you get across Pins 1 & 5. When taking this reading, take the reading several times with the motor rotated by hand into slightly different positions and report back the lowest resistance reading obtained. Expect to get a reading that is less than 120 Ohms and probably less than 60 Ohms.

 

If there is a motor fault where the coil resistance is low due to a motor coil winding fault. Then a situation could arise where the extra current drawn by the motor is supported by the DC Analogue controller [if it has a fairly high current output capability], but could trigger a DCC Controller that has a more sensitive overload protection capability or just a lower current power pack [say 1 amp for example]. Thus the loco runs under DC control even though drawing more current, but triggers the overload protection on the DCC system power supply.

 

Your DCC controller constantly re-booting is a symptom that would be seen if more current than the attached power pack can provide is being drawn through the controller. This re-booting is something seen quite often with the Hornby Select controller if powered by the factory default 1 amp supply. Which is why the very first question I asked was what controller brand / model are you using.

 

TIP: As a newbie poster on the forum, just be aware that the 'Blue Button with the White Arrow' is not a 'Reply to this post' button. If you want to reply to any of the posts, scroll down and write your reply in the reply text box at the bottom of the page and click the Green 'Reply' button.

 

See also – further TIPs on how to get the best user experience from this forum.

https://www.hornby.com/uk-en/forum/tips-on-using-the-forum/

 

[Kiwi Frazer]

Thank you for your detailed reply

I will have to get myself a Multimeter.

I am using NCE Controller.

[Fishmanoz]

A couple of other possibilities to check, can be done while waiting for the multimeter. 

First, you say you can program the motor bogie only.  Can you also run it on its own?

 

Then, what happens if you place the other bogie on the track but facing in the opposite direction?  I'm wondering if the insulated/non-insulated wheels are back to front. 

[Kiwi Frazer]

Greetings

I now own a multi metre

The mother board model number is R3346-PCB01

I ahve watched a few vids on youtube about how to do this.... and well... the only open circuit is 1 and 4.  1 being the J1 and the lug wiht the Arrow on it.

All other pin outlets and any other pair configuration are all closed.

 

In answer to Fishmanoz...   I tested that scenario - motorised bogie on the track first.... no reboot.... then once the second bogie hit the track - started to reboot.

hmm.

[Fishmanoz]

With non-motorised facing both ways, or only one way. 

If only one way but the wrong way to not reboot, all the wheels are reversed (insulate v non-insulated).  If both ways, use your multimeter across the wheels (each wheel on one side against every wheel on the other side).  If you get a short anywhere, then that set of wheels is most likely reversed.

 

Visual inspection should also allow you to see if all the plastic insulating bushes are on the same side or if one is reversed. When sitting correctly on the track, the insulated bushes on the wheels of both bogies should all be on the same side. 

[Kiwi Frazer]

Hello

I can get a reading on all wheels except the centre wheels in the bogie under the motor.   I can't get a reading on those wheels or any combination of wheels with them.

I am not sure how to get access to those wheels.  I am guessing the out two in that bogie are attached to the motor.