Does anyone have any tips for troubleshooting Marklin 3-rail AC locos? I bought a used set recently for my nephew, and my brother and I are stumped. I checked the powerpack output, and it ranges from 0-17 vac. I checked the track from outer rail to inner nub, and it's getting power. We applied power directly to the pickup "shoe" and the drivers, and no go. I took off the shell, and this is what I found: Could the circuit board be for Marklin Digital? I was surprised to see it under the shell. I'm able to turn the motor, and the mechanism turns freely, so I know it isn't jammed or stuck. I'm not sure where to go from here. What should I check on the loco?