Normally open, normally closed and make/break switches

A normally open switch closes its contacts when actuated (Gottlieb calls it an "A" contact); a normally closed switch opens (a "B" contact); a make/break has a common blade between an open and a closed contact (a "C" contact). Schematics draw every switch as it sits with the game switched on, reset, and the first ball in the shooter lane.

Systems

• Electro-mechanical

Related tips

• New to EMs? Do not adjust switches that work
• Why EM switch contacts get dirty
• File EM switch contacts
• Switch gap and adjustment targets
• Tighten a switch stack before adjusting it
• Adjust a leaf switch at the stack
• Look over every switch before first power-up
• Game stopped working after filing switches

Source: Repairing Electro-Mechanical (EM) Coin Operated Games to 1978, Part One, Clay Harrell (pinrepair.com)