lacquered circuit boards

[Martijn Meerts]

Before I start the more difficult decoder installs I'm working on for Domino (and which are long overdue ...) I started converting some of my own locomotives. I went with the Lenz Silver Mini+ instead of the Gold Mini this time, it's much cheaper, and the new + version has railcom (which is initially why I went with the Gold decoders, I really want to experiment with it..)

Anyways, I decided to pick what I thought would be a difficult locomotive with limited space. I went with the MicroAce Chichibu Railways Deki 200. The design of the thing is actually real nice, pretty much optimal use of space. It turned out not to be that difficult (once you figured out how to take the thing apart anyway), but one problem I've come across, is that it has a PCB which has the lights and related circuits on it (3 resistors, 2 capacitors, 1 transistor.) The problem with the board is that it's lacquered green, which makes it REALLY difficult to see the copper traces.

Has anyone come across similar boards, and possibly have a solution how to find out where to cut the traces so I can hook up the lights etc? I don't have any pictures yet, but I can take some tomorrow.

[CaptOblivious]

I have come across similar boards: Some Micro Ace boards have a black solder resist that makes it absolutely impossible to see the traces.

Solution: forget trying to trace the traces. In my case, I used the motor leads of a TCS M1 decoder (with TCS's "button control of the motor" functionality) to control the lighting board directly. Not an option in your case.

How hard would it be to make up a new board from perfboard or veroboard?

[Martijn Meerts]

The perfboard/veroboard I have is too thick, the shell wouldn't fit anymore if I used that. Haven't come across anything that's thinner either, unless I want to etch my own boards.

The board is also screwed in place, and the screws also keep 2 metal weights in place. I could chop off the ends, so I still have the screw holes and ligths though.

[inobu]

Hard to get but may work for your own pcb run.  In essence copper on Kapton

Pyralux




Inobu

[Martijn Meerts]

I went ahead and cut the circuit board, seemed the easiest method. It also freed up space to place the decoder.

Only problem now is that the shell won't snap on anymore, and I can't really see what's causing it. There's plenty room for the decoder and wires, and even pushing the shell on with considerable force doesn't flatten the wires, so those aren't in the way. I'll need to experiment a little.