i just started had Row 1 Ground Switch Stuck error pop today while playing the game. I did a handful of diagnostics that I found on the forum from simialr posts. I reseated all the connectors unplugged connectors on the board and restrated and did not get the message. After checking individual switches, I found that when I trigger the opto for the ball popper of the tardis, all the other switches worked normally. once I unblocked the opto all other row one switches were closed. I checked for loose connections and didn't find any....lastly I unplugged the opto from the opto board on the underside and the error went away and all the othter row one switches went away....I'm guessing I have a problem with the opto board, but would like to hear any other thoughts or diagnostics I might have missed.

Thanks for the quick reply.

Yeah...I was worried that it would require board repair....not my forte. Do you have a recommended repair shop? I see replacements for $99, as well.