Dashboard PCB Replacement (CJH Design)

[The Hairy Camper]

So, like I'm sure many of you have also experienced by now, the dashboard ribbon on my van is starting to fall apart in a few places. I've ordered a conductive paint pen to try and keep it working for now, but ideally I would like to upgrade in the near future.

I did an online search and found a couple of companies that do a replacement dash kit, but for what it is, it seems pretty expensive. Sure it would save time, but as my ribbon still works, I thought I would see what other users had done and see if there is anything I can do myself.

Then I stumbled across this:
viewtopic.php?t=125921

On page 7 CJH joins the group and makes an incredible design to replace the old ribbon PCB. He even made kits for people in 2018 (which I would love to get my hands on), but he doesn't seem to post or come on the forum much anymore. 

So, my question is, is all the information still here to get some new PCB boards made up? I barely know anything about PCB boards, so I'm hoping some people on here can assist me? If it's doable I will order some PCB boards myself and try to replace my van's ribbon.

Here is the final designs I think CJH made:

[The Hairy Camper]

CJH also appears to have/had a website with more information and a v1.1 of his PCB board.

http://www.cjh.me.uk/MyPhotobucket/albu ... 20v0.4.pdf

Anyone know if this is enough to try and replicate the board?

Cheers.

[slowcoach]

CJH also appears to have/had a website with more information and a v1.1 of his PCB board.

http://www.cjh.me.uk/MyPhotobucket/albu ... 20v0.4.pdf

Anyone know if this is enough to try and replicate the board?

Cheers.

Hi,
yes its a great shame CJH dissapeared after making such a fantastic kit.  But great news youve found that pdf - that is the same one that was printed out with the kit and posted out to the lucky ones who got one.  The printed board itself was obviously designed by him, so whether or not you can copy it is another matter, though he was clearly a community minded chap and not making any money on it, so i cant imagine a scenario where copying it would be a problem?

I have a rev counter, and if i remember rightly that wasnt really documented in the instructions, but its straight forward enough if youve got the noodles to assemble the board yourself.

Looks like youve got what you need to replicate it.

I would only say that the dash illumination is very dim with the specified resistors for those lights, so id reduce those values a bit, to get brighter dash lights.  there was loads of discussion about how they should be dim to avoid night blindness etc etc, but it was made too much of an issue and so its hard to tell theyre on at all unless its dark dark outside.  I modified that from the kit later on. other than that, its all perfect i think 

 

[The Hairy Camper]

Thanks for the reply slowcoach. I'd like to think he wouldn't mind me using his design, the guy offered to post me some tools once when I was struggling with some work on my van, so I think he's definitely a community minded guy like you say. I really would like to know what happened to him.

I've installed an aftermarket tachometer on my van and it is pretty straightforward. I suppose you could add something to CHJ's PCB design so it's easier to connect things? However, I remember Aidan saying that for Dashboards with a built in tachometer, the ribbon takes the signal from 1 wire and sends it to 2 different points on the Dashboard. So it could be as simple as adding a few more wires to CHJ's PCB?

I have read on hear the some people were concerned that the LED's could cause you to go blind!? Testing out some different resistors should be easy enough though.

That's great that you think I have all of the information to replicate this board. I guess I need to check out if the images I have are the correct dimensions first. I'll try and print them out today.

[Mocki]

Might be worth talking to these folks
https://www.purepcb.co.uk/contact-us/

[icosahedron]

AFAIK, CJH didn't release his PCB design files and you'll need them in order to have one made. There is, of course, nothing preventing you from reverse engineering his circuit or your dashboard and producing your own design along the same lines.

[The Hairy Camper]

I'm in talks with a company that say they should be able make a similar PCB. They say they will need dimensions of both the main PCB and especially the multiplug PCB to get things accurate though.

I have someone looking into it, but if there is anyone on the forum who has one of these kits and can post measurements, please get in touch.

[TwinTurbo]

I was going to nock up a PCB desing at some point, I have the circuit diagram I think , but this may help a lot.

PCB's that sort of size are ~£10 for 5 from JLCPCB, so ver cheap.

Rob

[TwinTurbo]

The dash ciruit diagram is arround online , and the diagram above is easy to replicate.  so either way it's not a big issue. 

The mounting centers for the bulb board and the LED placement can be measured off the cluster.

Is there any mention of the different versions of the dash in any of the documentation?

Rob

 

[The Hairy Camper]

Is this the dash circuit diagram you're referring to?



I know the wiring can be different for earlier versions of the vans. Some dash lights can be in different positions too I believe, but I'm not sure if the dash can be physically different?

[TwinTurbo]

yeah that was one I found in the WIKI. 

it's probably a couple of houts work to turn it into a PCB Layout , covering variations would be possible. 

If anyone has the POST85 Petrol one that would be good , may be able to work it out from here but it's a bit more trawling the diagram.
T25 Wiring
 

[TwinTurbo]

15mins and possibly 30% done on a roughing out..  based on the wiki diagram.  

once done will compare with the other project. 

[The Hairy Camper]

Cheers TT, all of this is another language to me. I wouldn't trust myself to get any of it right.

Appreciate you taking the time to contribute

[TwinTurbo]

i was planning on doing it anyway at some point. I was thinking more along the lines of a full width pcb and not have the fly leads , but that gets a little large and a bit more expensive. Theres so little on the PCB it's not really worth it.

[TwinTurbo]

So this is essentaily the diagram from the wiki reworked , I need to refernce the CJH docs to get the resistor values correct. 

the CJH PDF has a more up to date PCB with some caps to add damping to the guages and for better performace of the volt reg, the volt reg realy needs a diode across it too so will addd that. 

There's little documentaion on the oil warning system in the documentation, I will take a look at the VW wiring diagram and see if it's therre.