Could be multiple issues. Try a few things to narrow it down.

First, start a game and bang around the playfield with your fist. See if any switches trigger with vibration. If so, open the gap a little.

Second, it might be good to replace all the caps on the switches just in case. If you didn’t as part of the swap, it could be one or more faulty caps. And, replacing them isn’t a bad idea anyway since old Bally caps often fail causing weird problems.

If the situation still occurs, play some games and see if you can pinpoint when the reset occurs. See which switches are closed and report back. It could be a faulty diode somewhere.

I think your EOS switch is on backwards. Shouldn't the lane change switch be on the outside edge, away from the coil? So when the crank pushes against the switche stack, it opens the EOS switch first, and closes the lane change switch second? It looks like how you have the switch now, the opposite is happening. The switch with the fatter contacts is supposed to be wired for the EOS switch.

The wiring looks ok to me. The reason for a double stack on the right cabinet switch is because it’s a dual right flipper game and the lane change switch cannot be stacked with the EOS switches. Your old secondary EOS switch was missing a contact, so they tied the wires together to get the upper flipper to work.

From the clues you gave, my guess is the diode on the upper rollover button is shorted.
Test #1: hold the right flipper button in and press the top left through lane switch. If the game resets, the diode on the upper rollover button is shorted.
Test #2: hold the right flipper button in and trigger the bottom pop bumper. If the left pop bumper fires, the diode on the upper rollover button is shorted.

I forgot to mention to hold the upper rollover button down when performing these tests.

This may help:

may not help your issues, but that dual EOS needs to be corrected by all suppliers that sell that configuration.
it is incorrect for Bally games that have more than 2 flippers.

your left hand cabinet flipper switch may work, but the current involved requires heavy duty contacts to cope properly.
your right hand flipper switch contacts are severely pitted and should be changed, just a suggestion.

the first switch closest to the coil is the EOS switch and should have tungsten tipped contacts, NOT standard contacts, as you notice are on the second switch contacts that are for engaging the upper flipper.

lane change switches for a Bally are in the cabinet stacked on the flipper switch. These do not require heavy duty contacts but will still work fine if they do.

you could try correcting the set up for a start? also try adding some spark suppressing capacitors on both the flipper switches in the cabinet and the switches on the flipper assemblies. This is not for everyone but once done you help give long life to your expensive tungsten tipped switches and reduce noise from the spark generated when the capacitors aren't installed.

regarding the switch test, and it's probably a typo, but the switch test shows 'closed' switches, not open ones.

i mean no offence how my post may sound, but it's a shame that sellers of parts get it wrong sooooo many times and it's left up to the buyer to sort out, and if you're not any wiser in the sense of what correct and what isn't the you end up suffering through no fault of your own.

I not trying to hijack this thread, but I have a question related to it. I'm having some switch matrix issues on my Centaur causing some weird behavior. I know this because I recently purchased a Weebly switch matrix tester, and found the entire column number 8 to be nonresponsive using the switch matrix tester, but all checks out okay when manually closing the switches in the column. I watched that switch matrix video suggested by Nokoro but I'm still a little sketchy trying to follow it. My question might hopefully be a simple one. When checking for a "short" in a diode, does this mean that something metal is touching it, or is a shorted diode discovered only by using a multimeter? Just trying to understand it all. @ktuhde, you're more ahead of the curve than me maybe, but I'm getting there hopefully. I'm learning a lot from this thread! Thanks!

Thinking on it my post wasn't really helpful, so these are the correct dual EOS switches that go on flipper assemblies for Bally & Stern with more than 2 flippers: https://www.euro-pinball.de/en/a365-00046-0000-dual-eos-switch-assembly.html

These are the correct cabinet flipper switches without the lane change switch: https://www.euro-pinball.de/en/Cabinet-flipper-switch-Bally-ASW-A10-41.html

Diodes can 'short' in at least a couple of ways. A diode is basically a one way switch. Only allows current to flow in one direction (towards the stripe). If a diode is completely shorted, it allows current to pass in either direction. Need a meter to see this, but very simple test. This is rarely the case. More commonly, the diode is physically 'shorting' to something else. Standup targets close together and drop targets are likely suspects. All it takes is a singie strand of wire to cause an issue, so use good lighting to inspect switches.

You didn't say if the game is having issues while playing.

Thanks for the feedback. It plays normally, but certain switched lamps are lit and saved balls are achieved by rollovers that aren’t supposed to trigger those actions. Also, nothing happens in the two gameplay situations where balls are supposed to be deployed from under the playfield trough. I can message you privately if you want, so as not to distract from the OP’s issue?

Probably better to either start a new thread or post in the Centaur thread. I will quickly suggest you check the dip switch settings on CPU board and settings for high score (replay or EB?).

https://pinside.com/pinball/forum/topic/centaur-clubmembers-only

Already on that thread. Topics get buried quickly tho.

Dip switches are fine, and definitely a switch matrix issue. I’ll probably start a new thread, but thanks for the input.

Should have started a new thread. This confuses people when they come back to read old threads for help, especially in your case, has completely different issues than what the OP needs help with.

Also when you start your own thread, include a picture of your MPU board. There are different MPU boards available too, so that will help to know as well if you have an original Bally or aftermarket board.

If you can burn eproms for your game you can get the bally test chip from pinwiki:
https://www.pinwiki.com/wiki/images/3/36/Sco_testrom.zip

This will show ALL the closed switches in switch test, not just the lowest numbered one, so you can close selected switches and see which set activates the slam. You likely have a backwards or shorted diode somewhere in the wiring that is causing this.

The weebly mpu might have that test ROM built in. If not a couple of the other Roms on it should have the extended switch test too.

Your capacitors connect across the switch itself, both in the cabinet and the EOS, solder directly to the solder tabs for each contact blade.

Only for the high current, not needed on the lane change switch.

Great news, well done!

I've read about phantom coils energising and what I read was put down to that Bally bunched all their wires together and at random times the cpu picks up noise or a signal nearby as a closed switch and responds accordingly.

People have gone to the length of isolating coil power wires from the loom with it being better to no phantom coils going off at all.

I don't believe it's luck, adding a noise suppression device is such as a capacitor is what Bally did and is documented in their manuals/schematics, and it makes sense in such a volatile area with so much going on at the same time.

Regarding the resets, how close to 5VDC is the machines 5VDC supply and at various test points?