If it were me, I would look at the Player Up step unit (it is in the back box on my Bow and Arrow). There should be 2 coils on it, one to move to the next player and one to reset to player 1. Try activating the coil on the lower part of the Bakelite and see if it advances correctly and doesn’t skip player 2. You may need to clean the stepper unit if it is skipping that player.

Warning: I am new to working on my pinball, but was able to bring it back to life with help from people on here.

A507B89F-762E-43C1-A856-71C4C7311425 (resized).jpeg

There are two step units that work together. The Player Unit tracks the current player. The Coin Unit tracks the number of players. The Coin Unit should reset at the start of a new game which puts it at the 1 player position. It should take one step up as each additional player is added. The Coin unit doesn't reset until the start of the next game.

The Player Unit also resets at the start of a game to the player 1 position. It steps up when the ball drains until the player that drained is at the same position as the Coin Unit (e.g. until player 3 drains in a 3 player game). When the Coin and Player Units are in the same position and the ball drains, the Ball Count Unit steps up one position and the Player Unit resets to the player 1 position (e.g. from player 3 ball 1 to player 1 ball 2).

It sounds as if after resetting to the player 1 position, your Coin Unit might take two steps when player 2 is added instead of just one step. You can check by unplugging the game and manually advancing and resetting the Coin Unit. It should only ever take one step up and when it resets it should step back to the beginning all at once. If things look good when you do it manually start a game and watch what it does as you add a 2nd player. If it does take an extra step there's probably a mechanical reason for it unless you see the step up solenoid fire twice.

/Mark

Remember that the Ball Count should advance and Player Unit should reset when the Coin Unit and Player Unit are in the same position and the ball drains.

If that's not happening I'd check the 2nd position paths through both units that would be used in a 2 player game. Here's the schematic for the two units and I've added red arrows where the Coin and Player Unit wipers should be when the 2nd player drains in a 2 player game.
Nip It Player Reset 2 (resized).jpg

It's likely that either the path through the Player Unit 2nd position (grey-red wire to white-brown wire) or the path through the Coin Unit 2nd position (white brown wire to orange-white wire) isn't working.

If the circuit skips over player 2 maybe you can see in the schematic how the Player Unit position 4 skips over the Coin Unit altogether and always advances the ball count.

Your in good hands with @markg.
He helped me tremendously.
I will leave you in his very capable hands.

easy first check is tug the wires on the player and coin units to see if any are broken off. Also look for poor solder joints.

if that's ok, the hard part is probably identifying the wires. They all look grey?

with power off, you can use an ohmeter to find the issue. You'll be able to tell which wire on the ball count step-up solenoid is 75-8 because it isn't black, so stick one probe there.

the other probe will find 91-2, 56-2 and 53-2 when you reset the coin unit and manually step it up, poking the wire lugs at each step to find the wire that shows almost zero ohms. If you don't find wire 56-2 per mark's diagram, the problem is the wiper->rivet contact on the coin unit or the wiring from the rivet to the wire lug.

if you find all the wires on the coin unit, the problem is the 56-2 to 91-2 wiper connection on the player up unit that mark indicated or something is wrong with 56-2.