Why contact cleaner ruins silver contacts

Sparking breaks contact cleaner down into phosgene and free chlorine. The chlorine turns silver contacts into silver chloride, a white film that does not conduct. The normal black dust on contacts is silver sulfide, which does conduct. Soaked bakelite spacers can also shrink and change switch gaps.

Arcing breaks the cleaner down into toxic gases.

Systems

• Electro-mechanical

Related tips

• Do not use spray contact cleaner
• Cleaners for EM parts and cabinets
• Replacement switch contacts for EM games
• EM rotating contacts and score motor lubrication

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