I posted this to the prewar facebook group too, but it got no responses.

I've finally made some progress with my Genco Blondie. The 18v portion of the transformer wasn't working, so I removed those wires from the transformer, and swapped in a switching power supply-- and the game actually started! I got it to play for a bit, then it started acting squirrely, and something blew in the 120V circuit, taking out the fuse and tripping a breaker. I replaced the fuse, and the game lights up and the steppers reset, but none of the playfield switches are working. I'll figure that out.

Anyway, after replacing the fuse, I got to thinking about that 120v circuit, and exactly what it's there for. I traced the circuit in its entirety-- the wiring travels into the timer and a switch on the coin door... and that's it. I made a little drawing illustrating the circuit. It seems that the timer is largely superfluous in the home environment. I'm not sure what the switch in the coin door is for (it momentarily opens the circuit when a new game starts, and closes when the coin slide retracts). I cannot for the life of me figure out what the coin door switch does-- is it simply there to reduce sparking when the timer starts?

Ultimately, my question is whether there's any purpose in keeping the 120v circuit at all... it doesn't seem to *DO* anything other than turning the power to the game off when the timer expires. Does it serve any other purpose? If so, does it need to be at 120V, or can I run it at low voltage?

120v circuit (resized).png

Thanks Tim, that’s exactly what I’ve done.