Quoted from twista22:I have the same problem
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I had problem like this when my game was new in 2013. In my case one of the lights/flashers under the play field was “blinding” one of the opto sensors. Game interprets that as a dropped target and keeps trying to reset the targets to up position.
I inadvertently fixed my issue when switching to leds. As part of the led install I bent/adjusted some of the bulb brackets to make the led be closer to the insert. I think doing this stopped the opto from getting “blinded” and the reset issue went away.
As others have mentioned stern modified the design and put tubes around the opto so only more direct light from the other side of the opto would trigger it.
As a test you could put a piece of cardboard or something temporarily in the way to see if that helps.