It looks like the OP meant to post 2 pictures and we can only see one. I don’t know if I am looking at where a wire detached or a wire that was attached from the other side and it is the opposite side.
Yes, I saw the picture the first time. I see the tape residue that runs circumferently around the decoder. I was commenting on that darker streak that runs vertically in your picture.
Anyway, I assume you did not get a manual with the decoder. I did go to the MRC website to see if I could find one, because some of the other decoders seemed to have a wiring diagram. But I was unable to find your decoder listed.
I don’t have an MRC, but I’m on your side and was trying to help, hoping I could see somewhere where the blue wire broke away or where it shouldn’t have been soldered.
If I remember correctly, Railroad Mel was an MRC fan, but he is no longer with us. I hope you solve your problem.
Tomorrow I will solder the blue wire first, to the centre right dot and see what happens and if nothing, then I will solder the blue wire to the centre left dot.
You can magnify the wiring diagram. Seems like there are 7 connection points, with the blue wire in the center. Seems that the blue wire is associated with the lights.
If you put the decoder back into the tester, see if the headlights work. If they don’t, that would probably confim that your decoder is wired the same as the 0001637.
You can check to see if the wiring diagram is correct before soldering by hooking up an LED between the blue and white wires (don’t forget the resistor!) and then touch the blue wire to the pad that you think is the correct one. If the LED doesn’t light, reverse the wires on the LED to see what happens. If it still doesn’t light, try the other pad.
Looking at the circuit traces on the board in your picture, those two sold points appear to be on a common piece of circuit trace. That being the case, the blue wire could be soldered to either one and be correct.
