There were wholesale conversions of EM ball bowlers to SS. The machines are now essentially worthless.

For about a year, they seemed more relaible than the dreaded Chicago Coin mechanisms that used to gum up and stop or miscount. After a year or so of good operation, the solid state system started having problems. Then the company that made the conversions went kaputski. Although distributors who sold them had planty of spare part stock. A big problem with a SS conversion is that you don't get to hear the mechanisms clunking and clicking while the score reels turned. The silence of Solid-State electronics took away some play appeal.

Bally bowlers had more reliable scoring mechs, but the contact type pin versions, where the pins took abuse, required a lot of maintenance. United bowlers seemed to be the most reliable but Chicago Coin was king because they sold the most, had big ball versions and were the best value for operators.