Those two switches are daisy chained together & then to the 6 blue/green targets on the left side.

The white wire with a yellow band connects from MPU-J2 pin 4 to the lagoon saucer, cave saucer & then to the targets.

First I would check for a physical break in the white/yellow cave wiring near the playfield edge - these wires get caught & damaged on the edge of the playfield when you raise/lower the playfield. Follow the two white/yellow wires from the lug till it clears & goes into the loom. On my game these exact white/yellow wires have had the insulation scraped through from this.

Assuming the 6 drop targets are registering individually (not just the bank resetting) then it's not a MPU-J2 pin 4 connection problem, check continuity between the white/yellow common wire on the targets to the lagoon/cave white/yellow connection & also continuity between both lagoon & cave trap to MPU-J2 pin 4.

Check their are two white/yellow wires connected to one lug on both the cave & lagoon switch.

That’s not their purpose at least according to my game, if I bypass the rollover & lock a ball, the targets reset as normal.

Those two rollovers have a very specific function that is not always known about.

They come into play when you have a two or three multiball occurring & one of the balls lands in either the cave or lagoon saucer. At that point the targets for that saucer do not reset (they do not reset during mulitball) now this rollover target is ready to be actioned - when you roll the ball over the rollover towards the locked ball you get a speech call “help me” in essence the locked ball (the mermaid) is asking for help to be released.

This is my favourite speech call in the game - I always go for the locked ball in multiball to get the rollover & speech call.

I just realised you may not have know about how they work so they appear to not work, when they actually do - I should of thought of this first. I think a lot of people must think they relate to the the ball locking in & out the saucer as MrArt2u suggested. I probably did as well when I first got mine years ago & may have discovered it by accident with a shot to a locked ball.

Glad it's sorted. That's a nice Fathom you have, assuming it's the same one you had for sale - probably one of the best originals I have seen for sale in OZ & was a reasonable asking price too.

I never noticed the 50k score going with the speech call - That is well worth going for to get 100k.

With the 50k indicated next to the rollover & not scoring it with the rollover in general play probably added to people thinking the switch is not working or thought it was related to the saucer.

Glad you found this! yep, for sure, the nuances definitely add to making this game so great. The same thing drove me nuts in the 90s (pre-internet) when I first got mine until the penny dropped on day - I assumed it was a fault as I didn't have any reference.

Also worth noting is the home ROM version upgrade is a must as this utilizes the speech that is stored in the original ROM code but remains unused. The extra speech phrases added to this ROM fit perfectly just like they should have been there.

You need to upgrade the MPU U2 & U6 ROMS (only) to the HOME ROM V4 version found on this page below under ROMS in order to enable these extra call outs that are already stored in the Squawk & Talk board's original speech ROM.

https://www.ipdb.org/machine.cgi?id=829

Those extra call outs are only executed when using the Home ROMS. Their is also a skill shot feature added as well. The "Revenge" call out already exists in the regular ROMS - you get this call out when high score to date is beaten.

What may have happened is when you have fitted the cap to the cave trap switch, you would have needed to move the wiring out of the way for this switch to some degree to solder the cap in, the wiring for the rollover switch & the power wire to the memory coils are bundled together. That bunch of wires are so close to the edge they usually get squashed or the insulation sheared from the edge of the side rail. Mine have at least 3 wires squashed & insulation sheared.

You may have caused a short from an exposed bare wire(s), check all of the wiring carefully in that area for this & also the lugs on the coil that has the burned diode.