Frequency issues between 50Hz and 60Hz? That really WOULD be the cherry on the cake... sounds increasingly as though this whole business is a complete red herring, with no possible useful outcome.
One of the problems is that these locos are so rare over here, that the knowledge base just isn’t there, and anyone who DOES know, isn’t telling.
I don’t want to actually damage the existing installation, because who knows; but this is what the RailKing loco which has lost its electronics, looks like inside. I assume the small black box in front of the motor, is a rectifier, because this loco runs nicely (forward only) on AC or DC
The K4 looks like this inside. I’m guessing that the small pcb between the drivers, is the rectifier? From comparison, I’d guess that the brown and orange wires are rectified DC output? Then I could take those directly to the motor, and it would run (forward only) on AC or DC. Add a couple of branches to the lights and it would be a good “club nights” loco...
