The payline displays are operated by the SPN bus, they are connected by a series of what looks like ethernet cables, they also operate the reels. Re-seat all the cabling (with power off). There should be a cable that goes from the backplane to underneath the reel shelf, then several cables go out from there to the extra bet button controller, another one that controls all the LEDs under the reel window that show credits, lines played, etc. plugged into the left side'ish of the door below the reel windows, and another one that controls the bet line displays on the right side of the door if memory serves me correct. I will look at my machine tonight when I get home to verify, but I'm pretty sure those are it.