Hi Will,
For problem #1, I wonder if the switch on the AX relay that affects the 10's resetting is stuck closed for some reason. The first snippet is the reset circuit....just 3 switches involved, and the Motor 1A switch is common to all the reels, so it's probably working correctly. That leaves the "10'S UNIT RUNOUT" switch that should open when the score reel gets to zero, and the AX switch that should open when the reset is complete. I wonder if the AX switch were always closed, if you'd have the score reel just lock on until it got to zero, which would open the runout switch to break the circuit.
volley problem (resized).JPG

The EOS switch on the score reel doesn't come into play during the reset - only when the 10 pt relay (N) is involved in scoring. It breaks the current to the N relay, but the N relay isn't involved in the reset circuit. And since your N relay isn't locking on, it seems to be working correctly. While in the reset process, with the 10pt score reel solenoid locked on, is the N relay also locked on?
volley problem 2 (resized).JPG

Will, during the reset, when your 10 score reel solenoid is locked on, is your N relay also locked on?

Hi woz - would it make more sense for the RED-BLK wire on the other side of the AX switch to be the short location since the reel only locks on during reset?
My thought was that if the GR+RED wire were shorted, the reel would lock on every time the reel wasn't at zero during play and the 10's runout switch closed.

Hey woz, yeah, you're right - the other reels would be affected. I wonder if something is locking the N relay on during reset. But I can't see what that would be - the N relay doesn't look like it should be involved in the reset.

I'm leaning toward a problem with the AX relay as well - just because the clearances are so small between all the switch contacts and tabs on those things. I'd pull that relay out as far as you can, take out your magnifying glass, and make sure everything on the AX relay is working correctly with nothing touching that shouldn't be...switch leafs, switch tabs, screws. Tighten the stack screws first too, while you're in there.

It's hard to tell from the photos, but in the zero position, is that lower switch (closest to the metal frame) in the back closing?

For problem #2, as another test in addition to those DaMoib suggested, would it be helpful to fire the outer pop bumpers? They should give you 100 pts without making the score motor turn. That might tell you whether the trough switch/score motor is involved or not.

I'm curious too whether that 100pt/ball count problem happens with the playfield raised. We've all seen some shorts that happen when the pf is dropped and some wires get pinched.

Lots of test...good luck!

Hey Will - look carefully around the edges of the underside of the playfield for anything that will touch any metal or wires that might get pinched.

Also, I don't know what the underside of this playfield looks like, but is there a group of latching relays mounted to the underside? If so, they're usually held in place by a couple wingnuts on either side of the bracket that holds the relays. If all that's there on this machine, is the relay bracket all the way into its slotted holders and are the wingnuts that hold it there tight?

Man, @DaMoib....your mech is clean!

I'm glad it's working now, Will. I still don't understand why the 10's score reel coil was locking on, though.