I have a System 11 Radical! machine that occasionally exhibits odd behaviour, but I'm not sure how to go about tracking down the problem.

Everything seems to register fine in switch tests.

Occasionally, the R lights without the Lock Lane switch (38) being activated. I think it happens when the target behind the the lower drops is hit (28), but it could be one of the drops themselves (switches 24, 23, 22 from L to R).

Occasionally, at the start of a ball, the top drops don't reset. If you drain the ball without scoring, they reset fine when the machine sets up the ball. If I continue playing, the machine seems to notice eventually that the state is off and resets the drops. This problem did not move when I swapped the boards. Code issue?

Another behaviour I've noticed is since I cleaned up the spinners and they spin for ages, X Ramp Left (18) doesn't award a million if the spinners (top 17, right 29) are still spinning quickly - however the flashers usually do activate (and most of the time the locked ball is kicked if there is one) when X Ramp Left (18) closes, so I assume this is a code issue?

There are also occasions when 38 doesn't trigger at all - most noticeably when hitting that lane twice in quick succession when a ball is already locked (closing 40), leading to both balls locking and mega million mode being started early. I don't know if that's some kind of debounce getting fooled?

Any tips for what to look for would be greatly appreciated.

I ended up swapping the two drop target boards, cleaned the connectors and seems to have corrected the first issue I was having.

Sometimes the flashers don't go either, especially when both spinners are going nuts and the ball is going really fast down the ramp - if there's a ball locked at this stage both end up locked and it goes to mega million mode.

I'm wondering if adding a capacitor across the switch might help it read better? What kind of values would be worth trying?

I have finally managed to replicate this reliably in game:

• Right spinner (29 - col 4 row 5)
• Middle man (27 - col 4 row 3) - twice
• Top spinner (17 - col 3 row 1)
• Left X Gate won't register (18 - col 3 row 2)

I made a video:

Any thoughts?

Edit: I've found that by flicking the middle man gate hard, the switch will close twice, once as expected and a second time when the gate swings back. I guess that lines up with the behaviour I'm seeing. Now to figure out how to fix it.

I've also found triggering the middle man 3 times everything works as it should, 4 times it doesn't work again. This makes me think there's something in the code that's causing the issue.