Dapol O Gauge 08 Shunt Lights not working

[TypsJunction]

Hi 👋

I recently purchased a Dapol O Gauge 08 and ran it on DC for a period. On DC the top headlights at either end work when in the appropriate direction.

I then fitted a standard Bachmann 21 pin decoder to the model, which should allow at the press of a function key to turn on the bottom white and red shunting lights at both ends. However, the shunting lights only appear at one end and not the other. So I’m short, headlights work at either end however shunting lights only work at one end. 
Would anyone have any ideas why this happens?
I’ve struggled to look but I believe the shunting lights at the non working end are all connected up with no obvious wire damage which leads me to believe it’s a decoder / DCC issue. DCC isn’t really my strong suit so if it is the issue, an explanation on how to fix would be greatly appreciated.

Thank you in advance.

[meatloaf]

You need a 6 function decoder which i dont think the Bachmann one is.

 

On mine the bottom shunting lights are on F1 front and F2 back but as im using a prodigy controller i had to remap the rear lights to F4

 

But it varies depending on what decoder you have. 

[Kaput]

Bachmann have multiple 21pin decoders so you'll need to be more specific, product code and colour of the chip are needed (2 of the 21pin decoders share product code but are very different, the newer one is 6 function but 2 of the functions are logic level the Dapol 08 might need full power ones).

[w124bob]

Some prototype information, the top lights were rarely used even when new and by the mid to late 60's were more or less redundant. When shunting in a yard the bottom outer lights should display 1 red 1 white at both ends. The light nearest to the mainline would be the white one. On the mainline the leading end would have displayed the lamp code for the type of train being hauled (rarely express!)hence the top white light, light engine moves would have required one white at the front and a single red at the rear. Now the reality, the lights are very feeble, only 40watt bulbs at 110volts behind a very dirty fisheye lens . Pretty much invisible during daylight and glow worm at best during darkness, I would usually put a proper paraffin or battery tail light on the rear for a mainline run. 

In model form I really wouldn't bother with working lights and particularly on a Jocko. One final point the actual light switches are under each individual light, not in the cab.

It's basically the way the lighting circuit board has been wired at the factory is not prototypically correct, there no "headlights" on an 08.

Edited April 24, 2022 by w124bob

[TypsJunction]

On 17/04/2022 at 14:57, Kaput said:

Bachmann have multiple 21pin decoders so you'll need to be more specific, product code and colour of the chip are needed (2 of the 21pin decoders share product code but are very different, the newer one is 6 function but 2 of the functions are logic level the Dapol 08 might need full power ones).

Hi,

Taking a look at the chip now, on the top it reads Rev A and on the bottom SoundTraxx and MC1H10421P. All on a green PCB. I believe the chip was purchased in 2016.

2 Photos of the chip are also attached.

So, would this not be a 6 function chip? 
Thank you

[Kaput]

Pretty sure the Soundtraxx ones are only 4 function.

[Nigelcliffe]

57 minutes ago, TypsJunction said:

Hi,

Taking a look at the chip now, on the top it reads Rev A and on the bottom SoundTraxx and MC1H10421P.

 

 

 

I put the model number into Google.  The first hit was this page

https://soundtraxx.com/products/dcc-mobile-decoders/mc1h104p21/

 

(same result from DuckDuckGo and Bing ).  

 

 

- Nigel

[TypsJunction]

38 minutes ago, Kaput said:

Pretty sure the Soundtraxx ones are only 4 function.

 

5 minutes ago, Nigelcliffe said:

 

I put the model number into Google.  The first hit was this page

https://soundtraxx.com/products/dcc-mobile-decoders/mc1h104p21/

 

(same result from DuckDuckGo and Bing ).  

 

 

- Nigel

Ah thanks, I suppose that’s the answer!  - 4 Function it is.

 

Would this be the one for the job to allow all lights to be controlled, LaisDCC 21 Pin 6 Function decoder?

https://www.ebay.co.uk/itm/Laisdcc-21-Pin-Dcc-Decoder-6-Function-/125150128114?mkcid=16&mkevt=1&_trksid=p2349624.m46890.l6249&mkrid=710-127635-2958-0

 

[Kaput]

I think the Lais one has the correct type of functions for  the 08 but it might depend on the version of your 08 - I believe the 2nd batch have extra lightning functions and might need an 8 function.

[TypsJunction]

14 hours ago, Kaput said:

I think the Lais one has the correct type of functions for  the 08 but it might depend on the version of your 08 - I believe the 2nd batch have extra lightning functions and might need an 8 function.

Ok thank you, how do I find out if my model is from the second batch?

[Nick G]

7 hours ago, TypsJunction said:

Ok thank you, how do I find out if my model is from the second batch?

 

 

Early versions had top light and 3 lights along the bottom, late version just 2 lights at both ends. 

[TypsJunction]

Hi, I purchased a 6 function LaisDCC decoder and I’ve now put it inside the 08. 
Now, the shunt lights at one end are always on, whilst the rest of the functions operate normally.

F2 turns on/off the shunt lights at only the one end (like before) whilst F3 makes the other end lights go ever so slightly dimmer and seems to make the loco jitter with no influence of movement or stopping from the controller, forcing me to switch the power off. (Photos of the lights before and after F3, become slightly dimmer, attached)
All seems rather odd 😂

 

Any help on wether these issues can be fixed would be great 

Thank you

[Nigelcliffe]

Someone needs to nail down which version of the MTC-21 pin decoder standard Dapol used.  Unfortunately, there are two different standards for 21pin sockets and it often causes problems.   That difference is in the high function numbers which can be "logic level" or "full voltage".      

 

A handful of decoder makers offer decoders which can swap between the two standards.  Digitrax and Zimo both have decoders in their ranges where a users CV-change will swap the decoder between the two standards.  (NB for Zimo its the non-sound decoders which can do this, not the sound ones).   

 

 

Lais say their decoder is "logic level"  see:
https://laisdcc.com/LaisDcc_Decoders_Manual_V2.pdf

 

 

So, the obvious thing is to try a "full power" output decoder in its place.  

 

 

- Nigel

[pauliebanger]

Since Dapol fitted ZIMO sound decoders to their Factory Sound Fitted option, (MX644D) it's reasonable to believe that these 'full voltage' decoders were used during model development.

 

Hence, for the first batches, (long hinges on the engine room doors?) a decoder with full power on all 6 Function Outputs will operate the model out of the box.

 

Using a logic level decoder in these models will result in 'always on' rear lights in all cases. It can be worked around by modifying the model's PCB and wiring, but the simple solution is to use a full voltage decoder instead. (or one which may be changed from full power to logic level, as Nigel suggested).

 

For the later batches, Dapol not only changed the requirement to include 'Logic Level' on FOs (AUXs) 3 and above, but also remapped the lights as well. For these models, a logic level decoder is required the Lais being an example already mentioned. ZIMO have a sound decoder MX644C with the logic level outputs required, but most brands have an offering in sound and non-sound to match these requirements.

 

The newly available ZIMO MS440D and MS440C are full power and logic level respectively, but each has the ability to be converted to the other by user CV changes, so each will work in either batches, much like the earlier MX 21 pin non sound decoders. I don't know of any other brand of 21 pin sound decoder which has the capability to become either type, but they may exist.

 

So, before deciding upon the correct decoder, it's important to determine which variant of the Dapol model is to be equipped.

 

Please note that the lower middle lamp is a dummy on all Dapol 0 gauge 08 models; there's no LED fitted.

 

Best regards,

 

Paul