one of the score switches is closed ,1- take playfield plastics off. 2- Look behind the rubber rings at the switch and make sure they all have clearance.   Could also be scoring switches on the targets or even the pop bumper score switches, Underneath each  bumper. As the game scores does it make a certain sound??  track down that sound .  Is the game scoring 10's  100's or 1000"s . If it scoring say 100 points check all  the 100 point switches.  can't be to hard to find . And the scoring issue is causing the other problems i would say...