You need to repin the connectors, reseating them is a temporary fix. The numbers jumping around is the data being lost from the connector at the mpu to the decoder on the display. 99.9% of these games of this era need the rectifier board rebuilt with new bridge rectifiers and connector headers. If the fuse clips look tarnished or burned, those need to be replaced as well. Get the power and connectors nice and rebuilt and a lot of the other problems you are seeing will go away.