I havent dug very far into this.
But something I have noticed the past month or so which just started getting worse:
During multi-ball or anything really "crazy" a good chunk of lights go "rainbow" on me instead of illuminating the correct color.
It either starts or stops at 8 on the YBR (i need to record or better document exactly what lights this affects).
I lifted up the PF last night and reseated the data cables going to the big board that has YBR #8 on it (W2 i think?)
It is certainly happening less now, but still came up a few times when i played it twice after. Since it comes and goes, and mainly happens during increased activity on the PF, I am thinking loose cable in the data chain somewhere.
Just putting this out there in case other folks have experienced this. Will report back as I check more things out this week.