RMI and STBY were connected to a CPFlight card that is not produced anymore and for that reason it was not possible to conncet them to the MIP board and were unusable.
The card gets the inputs of the baro knob (button and encoder), the 5 buttons of the STDBY and the 2 knobs for selecting between ADFs and VORs. The card also has the LEDs for backlit of buttons and signs.
The idea to fix is to keep the card as it is because the components are drectly mounted on it and perfectly fits with the panel. I am pretty sure that if I buy a panel the measures will be different and it will not look nice once mounted in the frame.
These picture shows the front and rear view CPFlight panel with the STDBY-737 card once dismounted from the MIP.
With a multimeter I looked for the connections used by buttons, encoders, switches and when found I decided to cut the connection in the STDBY737 card and connect them directly to a LeoBodnar card. You can see in the following picture the soldering with the cable to connect to the LeoBodnar card.
I could not recover the rotaries to select between ADFs and VORs of the RMI. Probably my knowledge of electronic components is too limited.
All the other components work perfectly.
At the end I decided to use the + and - buttons of the STDBY to select ADFs/VORs. Not very realistic but it works and I do not need to change the light of the STBY gauge so I am not loosing anything.
XPlane see the LeoBodnar board as a joystick. It has been very easy to associate each push button and the rotary to the proper event with the XPlane menu of the joystick,
The LeoBdnar board need to be configured to recognize the knob but it has been very easy following the documentation and immediately recognized by XP.
I have not been able to light the LEDs because could not really understand their connection in the CPF board. I will have to get back to them sooner or later as I suspect that it s only matter to find the proper connection to have them working. Ideally, I will connect the LEDs to a power supply so that they stay ON all the time but first I have to find how to do that!
In conclusion I recovered the panel and its full functionality with some trick. In particular the selection ADSs and VORs happens with the + and - buttons of the STDBY.
Backlight still pending.