Hi EM folks! mikala was kind enough to point me in this direction.
Two weeks ago, I started a thread in the "Restorations Documented" section chronicling the restoration and repair of my Duotron . (https://pinside.com/pinball/forum/topic/duotron-1974-or-how-i-learned-to-stop-worrying-and-love-the-relays)
To summarize what is in that thread as of 2/6/2019:
It mostly worked when I purchased it 10 years ago.
I spent several years rehabbing the damage to the case.
As time went on, things started to work less and less well.
About 2 years ago, I put the machine in storage in my parent's basement while we moved. When it went in to storage, it did not work. Player 2's score would not stop resetting.
Now, I am cleaning the machine and learning how to troubleshoot. Pinrepair.com's EM repair guide is open on my tablet constantly while working.
I have recently finished rehabbing the score reels for Player 1. They actually cycle smoothly now!
The anti-cheat switch on the door is pretty mangled. I'm going to order a new one.
I've begun bulb replacement. I've already swapped out 27 of the 95 with LEDs. I'd like to do the whole game after seeing how much of a difference it makes.
Many of the bulb sockets are a bit dodgy. I will be taking Pinrepair.com's advice on how to fix many of them.
Neither inserting a coin nor pushing the start button triggered the "S" relay. It's supposed to lock in via its own switch and a motor 2B switch. Time to check the motor 2B switch.
When tripped manually, the motor cycles one position. At this point, a relay on the motor is supposed to actuate the "SB2" relay and the total play meter. Neither happens. When I manually trip the "SB2" relay, the motor begins running and will not stop. I'm going to check how much voltage is making it to the "SB2" relay coil.
While the motor is running, the first player unit is supposed to reset to zero. I already have it set to zero. It doesn't move. I think I've located the P3 switch stack on motor 1A & 4A. 1A looks good. 4A looks not quite right. the contacts that I have circled never actually touch and are filthy.
I've met some very helpful people over in the "Restorations" area, but still have a ton of EM specific questions. I'll be numbering each question to hopefully make them easier to respond to.