So CV has a vertical up-kicker about halfway up the right side of the playfield, right? When you first turn on the machine, immediately after it boots up, that coil rhythmically dry-fires every 2 seconds or so. It does this between 5 and 8 times, then stops. After that the machine functions normally, including that VUK. (If you open and close the coin door, it does the same thing.)

I checked and cleaned both sides of the opto, and they seem fine. Everything appears to be hooked up right. The opto board under the playfield looks good, but I don't really have any way of testing it. The opto has to be working, because it works every time during game play, without fail. The prior owner indicated that he replaced all the boards in the back-box, and they look fresh and new. He did not indicate when the weird coil firing started, but he was aware of it and he showed me the issue.

What the heck would make this happen?

Thanks,
Mike

Replaced the optos, problem has been solved.

Thanks to everyone who responded.

Mike