Adjusting more than a few switches means something else is wrong

Unless a game has been butchered, only about 5 switches in 100 should need adjusting. If you are re-gapping many more, stop and rethink before making things worse.

Systems

• Electro-mechanical

Related tips

• New to EMs? Do not adjust switches that work
• Tighten a switch stack before adjusting it
• Adjust a leaf switch at the stack
• Why EM switch contacts get dirty
• File EM switch contacts
• Switch gap and adjustment targets
• Normally open, normally closed and make/break switches
• Look over every switch before first power-up

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