On Big Hit, the score and run reels are reset via their 'runout' switches (at the reels), a separate switch on AX (each), and either a switch at score motor 4A or 1A (they're split three on one, three on the other).

Motor 1A has the 10,000s, 100s, and 10s runs.
Motor 4A has the 1000s, 10s, and 1s runs.

So there are a few possibilities:

- As Ken notes, the 1A and 4A score motor switches are marginal (cleaned, gapped).
- The AX relay isn't latching fully, and/or the six switches that govern the score reel reset aren't fully working.
- AX is unlatching early. The AXR (AX reset) coil should only energize when all six score reels reach 0, so this seems least likely.

If you watch AX while it does this, what does it do? Does it latch and stay latched, or does it unlatch early?

OK, so then the question is whether that's due to AX not having latched fully in the first place, or whether AXR is energizing to release it.

So one experiment to try is to manually activate AX, making sure it's fully latched (but don't over-press on the switch ladder and let switch blades pop out of their slots). If it works OK, then that suggests AX isn't able to fully latch on its own.

But if the game still doesn't reset fully, and AX unlatches early, then the thing to investigate would be the zero position switches on all six score reels. They all need to be closed in order to complete the path to AXR. It's possible that several are out of adjustment, allowing them to close before the reel reach 0.

Can you post a picture or two of one of the reel's switch stacks while it's not on 0?

Pictures are worth something (or so I'm told).

Glad you got it sorted!