The score motor will run until both players scores read 00000. Start there before worrying about anything else.

Do the score reels move freely if you advance them by hand? This may be a better starting point then doing the jumper: http://www.pinrepair.com/em/index2.htm#reels

If you manually reset them to 0, I assume the sequence stops?

If so, put it on 2 players and advance to the 2nd player. You can start to diagnose if the reels are getting power by hitting a 100 point switch (center bumper should give you this). See if the scoring advances the reel. If you hit the 100 point 10 times, does the 10k advance?

I’d also hit that link above to get familiar with the stat up sequence.

Without looking at the schematic, that unit should be independent of the scoring. You can test by getting to player 2 and then manually pulsing the 100 pt relay in the backbox. If tripping that relay doesn’t pulse the score reel, you have a starting point.

I’d look at the schematic to see what differs when scoring 100 for P1 vs P2. Most likely you just have 1 switch in that sequence that delineates which circuits are engaging.

However, after typing this out the fact that you’re not getting a reel advance during normal gameplay seems to indicate there may be a problem with the coil(s) related to those reels. Any loose wires? Read the “testing coils” section on http://www.pinrepair.com/em/index3.htm#low