Not Used
Matrix column 4, row 6 · not used ·
Wiring
- Column 4
- Green-Yellow J206-4 · U20-15
- Row 6
- White-Blue J208-7 · U19-9
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 4 (J206-4, U20-15) and row 6 (J208-7, U19-9). 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