don't have the schem for that game, but a typical circuit would be player unit wiper -> 9th position switch on reel -> 1pt relay switch -> 10 pt relay coil.

with all players having the problem, check the wiper finger and the 1pt relay switch.

if ya got a pic of your schem (the area that powers the 10pt relay) someone can confirm how wrong all at that is

it's the pretty standard circuit marked in red below.

when you checked the 1-9 score relay (called it 1 pt relay previously), were you looking at the switches on it? You care about the switch with the BLU-Y and G wires on the blades.

if nothing obvious, with game on player 1 and with the 1's reel displaying 9, jumper the BLU-Y to G and see if the 10's reel coil powers.

you can also use a voltmeter with one probe on the grey wire (green dot on below) and other probe anywhere along the highlighted path when holding the 1-9 score relay armature down on the coil top to see where the voltage drops.

1to10_rollover (resized).jpg

it seems pretty unlikely that the 9th positions switches are not adjusted right on all 6 players ... unless someone screwed them all up.