Friend of mine has a 8 ball just sitting and not working. Went over to see it and after fiddling a bit and a few fuses later she was running but the poor girl was worn out. Right flipper plunger was melted into the coil sleeve, plastics shattered everywhere, bulbs shattered due to missing plastic, rubbers worn out, and the play field missing a fair chunk of art.
The boards look good and the game does still play. The battery has not caused and board damage at all.