There are several different System 11 displays. Some have individual boards; some combined boards; some are 16-alpha while others have some alphanumeric, some numeric, and credit/match display. Which shuffle bowler is it?

kaz1961 Looks like you should be fine with early System 11 7-digit displays.

Exactly. It's functionally the same transistor, but it doesn't blow up instantly if a higher-voltage wire accidentally touches its circuit due to a fault on the playfield. Just a little more robust, and a slight bit of insurance against ignorant folk working on the game with the power on.

Damage to your switch matrix is normally due to a problem in the cabinet - almost always an intermittent short from solenoid voltage to the switches. Lane Change switches are a common culprit, since they are stacked alongside the EOS switches on the flippers. The Rottendog board may be immune to the problem, but it's still a problem that needs to be fixed. The board isn't capable of blowing its own transistors like that, unless it is severely damaged somehow.

You can heat the ends of a urethane belt and push them together. Here's how to do it without melting them off: