Cleaning dusty optos

Wipe a dusty opto with a cotton swab dampened with glass cleaner, then dry it with a clean swab. Do not blow optos off with canned air: the gas comes out cold enough to damage them.

Systems

• WPC Alpha-Numeric
• WPC Dot Matrix
• WPC Fliptronics
• WPC DCS
• WPC-Security (WPC-S)
• WPC-95

Related tips

• Testing an opto receiver
• Opto parts to keep on hand
• Opto styles used in WPC games
• Checking LM339 comparators on opto boards
• Flipper cabinet opto switch boards
• Checking an under-playfield opto board for bad LM339s
• Some WPC-95 optos can fail even when they test good
• Opto wavelengths: 880 nm and 940 nm

Source: Repairing Williams/Bally WPC Pinball Games from 1990 to 1999, Part Three, Clay Harrell (pinrepair.com)