It is not.

Listen to ALY, it's going to happen.

You look at it, make a guess, and reflow some solder. This video is not the best, but is very voyeuristic which excites me

Good picture you can see from Vid
https://pinside.com/pinball/forum/topic/vids-guide-to-bulletproofing-williams-system-6/page/2#post-962763

Ha, we've all been wishing for a way to test the back of the boards with a DMM without removing them forever
Rip it out, start re-flowing some solder, put it back in and test it. It's not the most pleasent thing, but it doesn't take that long.

EDIT: Or to put it another way, the issue with bad solder connections is they are hurting the continuity betwixed the back of your board, and the front pins, that connect to the rest of the game. Thus, they must be removed.

W....T....F??? Wow that's a new one. Although pins do suspiciously fix themselves to make you happy, and then pull the same garbage after to make you cry again. DH uses standard balls which I have always heard can get magnetized over time and fresh balls will help with some issues. I haven't heard them related to this issue but crazy shit happens all the time with these things.

The way things have been going for me lately, I'm big on the 12v being low and having to jumper the power board. So if this starts going on the fritz again, keep that in mind. 12v in my Pin Magic was low causing my DMD to go out etc. Diff'rent systems for sure, but just keep it in your back pocket. HOPEFULLY you wont need it.

Now finally get some drinks and kick back with some DH on a Friday. Oh and get some hotdogs.

Ha...as I said right before, get in with your DMM and test the volatages on the power board. If your levels are too low, it can casue a wide variety of issues like we're seeing here. "How can this all be related" I've said a million times...power is one of the answers.