Quoted from mikepin:The reason is the connectors are SHIT and very poor design. Early Bally ss and Sterns did it ALL the time as well. You THINK someone would have learned from that . GI connectors on ss Bally and Williams games been a problem forever...
At the time, there wasn't an incentive for pin makers to design/use components that would last more than 5 years in operation. Probably a bit of planned obsolescence going on.