I got a Big Hurt that had some errors when I got it. I've had one before, so figured it was in the optos. I found one of the larger resistors(?) had fallen off the opto board. It looked fine otherwise and it sounds like it happens from time to time with these boards so I re-soldered it to its home, oriented the same way as the one next to it. That cleared the opto errors and now there are no errors of any kind reported. However, a strange thing still happens every time the lower right field opto is activated by a ball passing through its orbit. The cabinet makes this energized vibrating effect until the ball has gone down to the left flipper, so for a few seconds. The other optos don't cause this to happen so I guess something related to the right opto on the main opto board isn't right. If there's no error, then why is there such a heavy energizing going on with this?