In your pics, trough switches 1-3 show closed, which means no balls for optical switches. Trough switch 4 (4th switch down on 4th column) shows open, meaning a ball is blocking that opto pair. Gravity shouldn't allow that to happen.

You either have bad trough optos or a worn trough causing balls to not roll all the way down to trough switch 1.

While in switch edges test, wiggle each trough board connector. If any switch triggers, rebuild both female connectors and closely inspect both trough board male connectors.

If nothing triggers, with 5 balls in the trough and still in switch edges test, smack the trough assembly a few times with the handle of a screwdriver or your fist and see if that triggers any switches.

The female connectors, especially the outside one, are always suspect. A cracked leg on any of the 12 optos (24 LED legs) on the trough board can also cause what you're seeing. If the boards are original, remove them and inspect them closely (if you haven't already).

Any optos working intermittently makes all the other optos in the game suspect. Games don't like when switches are intermittent and will sometimes put too many balls in the shooter lane, like you're seeing.

Should be able to test the skill shot optos with a finger or big standard screwdriver. Try vibration in that area while in switch test too.

How do the switch matrix connectors on the bottom of the CPU board look? Rebuild connectors if either look flakey. Also closely inspect the 10 opto board under the playfield. Any bulging capacitors or flakey connectors? If all looks okay, reseat all the connectors.

That is correct, but again, you aren't using the correct wording. Launch ball, ball exits scoop, then ball ejects from the trough into the *shooter lane*. Shooter lane switch is very different than trough switches. Please use the correct terms.

The advice above to check the 12 volts is good advice. Didn't notice you have a colordmd.

Have you tried a factory reset, as suggested above? If not, give it a try. Also couldn't hurt to reset both ends of the ribbon cable that goes between the CPU board and driver board.

If you haven't done this recently, give it a try. The CPU board tells the driver board to fire the trough kicker through that cable.

Still no love? Put the game into switch edges test and pound on the playfield with your fist. No switches triggering? Remove all the balls and try pounding again. Still no switches triggering? Take a pic of the switch matrix on the display (with the balls still removed) and post it here.

I see you have NVRAM on the CPU board. Is that new?

As much as I trust Rob's boards, I've seen some goofy NVRAM errors. If you can borrow one, try a known good CPU board with your game ROM. If another board doesn't fix it, it will at least eliminate the CPU board as a suspect.

The back side of that board doesn't look great, especially considering it's an aftermarket board, but rebuilding the female side of J3 is probably your next step.

Link below tells how to rebuild connectors with pass thru or looped wires (like J3).

https://pinside.com/pinball/forum/topic/idc-connector-question#post-6323841

Nice work sticking with it and narrowing it down. You're almost there.