we need the schematics. See in the JPG "Full House": The pulling Coin-Relay closes (encircled green) its switch - the Reset-Relay starts pulling-in. The Reset-Relay establishes Self-Hold-Current by closing (encircled orange) its switch. The Reset-Relay stays pulling until all the Score-Drums (encircled red) switches open as they reach their position-Zero.
On the bottom of the JPG You see "encircled blue": The motor rhythmically closes its switch because the motor is turning - the "Switch on the pulling Reset-Relay" is closed. AND (in Full House) - encircled brown: The Coin-Relay must have quit pulling so its switch is closed.
Want to try --- do not start a game by pressing the Credit-Button - do not start a game by pressing the armature on the Coin-Relay --- do: Press the armature on the Reset-Relay - try "press and let go" as well try "press - press - press".
A picture taken with an mobile phone camera of that area is good enough ---but we must see the wiring in YOUR pin. Greetings Rolf