I had the same issue with the "Ransom" board....It was cracked cold solder joints on the board...reflowed those and fixed it 100%.

Put some flux on the pins, touch the iron to each pin to melt the solder, and add a little new solder. Best practice would be to remove the old solder first with a desoldering tool. I only remove the old solder if it looks bad (cloudy) after reheating it.

I'm confused here. You said you replaced the connector. I guess i'm assuming both the female connector and the male header pin.

If you didn't replace the male header pin, yes, that's where the issue lies. It is either cold joints or a lot of tarnish on those pins, more likely the former.

I'd just replace the header pin.

That'll fix it!

If you look really closely at the back of the board, you'll see those cold joints. It'll look like a little circle around the pin. Really tiny to see though.

My advice would be to buzz out each pin before putting the board back in though, i.e. making sure you have good continuity from the pin to the trace on the back.

Good luck!

Here is a photo from another post here on Pinside that shows a good idea of what to look for......
190814.jpg

https://pinside.com/pinball/forum/topic/white-water-resets-when-cold-and-after-vacation-planner

Good luck!

Good pic Trooper.

I get happy when I see cold solder joints. Usually means I've found the culprit and it's an easy fix!