STTNG had SEVERAL (I think four) optos out... But never got a technician alert.
Only figured it out when a divertor arm got out of alignment and the game couldn't clear balls/constantly ball searching forced me to comprehensively check it out.
Come to think of it, I RARELY get an error dot from TNG. Is there a way the tech alerts could be disabled/set to absurd settings that won't detect anything?
When I did a real evaluation, I found previous owner had sloppily soldered some connections directly onto pins of trough board and the 16-opto board. Had to remolex them as well as opto fix. And had to fix thin copper wire of coil to connector on the solenoid that drops the drop target. Don't know how long ANY of those problems were there because of absence of tech alerts and initial unfamiliarity with how game should play.
But now I THINK its working great (now that I finally fixed the reset when Borg ship launches ball)!