Great to hear you are making some progress . I love fault finding EM's .
I think the "rugel ruckgabe" relay is the ball release relay , given you have a multi player game.
In order to fix the game, you need to understand how it works (as no doubt you can appreciate). This is where the paperwork will help a lot, once you get it.
The startup sequence must be completed before the game will work (as Millsy has said).
The Tilt relay can only be activated by one of the tilt switches so there must be something wrong in the Tilt circuit somewhere.
For now, I would suggest disconnecting the Tilt relay (by desoldering one of the wires connected to the Tilt coil lugs). The Tilt feature is not critical to game play anyway. I suggest this as you need to tackle one problem at a time , and the Tilt issue can be dealt with later.
Does the Hold relay (Halte) still energise when you start a game (since you adjusted the switch on the start relay) ? Not sure what the purpose of this hold relay is , but would suspect it should normally be deenergised. Maybe whatever is triggering it , causing it to stay energized, is why the score reels don’t advance when you activate a target switch etc?
