Not Used
Matrix column 8, row 3 · not used ·
Wiring
- Column 8
- Green-Grey J206-9 · U20-11
- Row 3
- White-Orange J208-3 · U18-5
Location
- Not on the playfield map: not used in this machine.
- No callout on the location map
Service log
Everything you record stays on this device.
Service notes: In the switch matrix at column 8 (J206-9, U20-11) and row 3 (J208-3, U18-5). Gap 1/16 inch; clean by pulling card stock through the closed contacts, never a file. One switch that fails T.1 is its gap, the wire at the lug or its diode; a shorted diode makes the whole column or row misread. A whole column dead is U20 or the J206 pin, a whole row is the row comparator. A3 Switches and optos
Appendices:A3 Switches and optosA5 Power driver boardA1 Multimeter basics