Hi guys, pretty new to EM repairs. I bought a 1977 Gottlieb Jet Spin last weekend that wont start. The lights for player 4 are always on, and the game over relay is always energized. When I hit the start button, all score reels reset properly and the lights in the backbox cycle through the player but the 4th player ones stay on the entire time. I've checked the Z1 and Z2 relays, AX and BX realyas, the game over and start relays, all seem to be adjusted correctly, as well as all of the score reel switches. All stepper units have been shined up and Teflon lubed and move freely also.
I don't have a schematic - what else could be causing the game over relay to keep pulling in?

Pic shows how player 4 lights stay on.

Thanks for any help - Don

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Any help appreciated....

Thank you, I'll dig through this in detail tomorrow in front of the game.

So now that I know the entire startup sequence, what could typically be causing the game over relay to remain energized? Slam switch is open

Schematic on the way from Pinball Resource.