New to EMs? Do not adjust switches that work

Beginners who clean and re-gap every contact usually create new faults. Inspect everything, but adjust only a switch that clearly differs from several neighbours of the same type; otherwise just tighten the stack screws.

Systems

• Electro-mechanical

Related tips

• Tighten a switch stack before adjusting it
• Adjust a leaf switch at the stack
• Adjusting more than a few switches means something else is wrong
• File EM switch contacts
• Switch gap and adjustment targets
• Normally open, normally closed and make/break switches
• Game stopped working after filing switches
• Bend switch blades at the stack, not along the blade

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