Not Used
Matrix column 1, row 1 · not used ·
Wiring
- Column 1
- Green-Brown J206-1 · U20-18
- Row 1
- White-Brown J208-1 · U18-11
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 1 (J206-1, U20-18) and row 1 (J208-1, U18-11). 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