I have a newly acquired Williams triple action machine, unit will turn on when plugged in switched on and left flipper pressed, but then nothing. Tripping the coin lever something energizes, but no ball is loaded. Score shows all zeros, no tilt warning is on, but the ball count never changes. I have set the spinner things in the back board to their start positions. I do have the original wiring diagram, and instruction sheet that were in the machine, but I’m used to read automotive wiring diagrams so I’m a bit lost. Looking for some insight or tips on what to check/test next, where I should have voltage things like that.

Sorry it is a triple action, see what happens when I post early in the morning.

After inserting a coin, I can hear something try to energize, after that pressing the flippers or button on front of unit ( is that the replay button?) does nothing.

Yes I have pressed the replay button, nothing happens. The score shows all zeros, never get a ball count, or bonus count, and no drop targets pop up. I plan on doing a cleanup of the connector pins for the backboard, as well as cleaning of the contacts on the the wheels in the backboard. The machine sat unused for 15 years in a basement. Thank you for the help.