Lamp 74

L74

Vault Green

Matrix column 7, row 4 ·  

Wiring

Column 7
Yellow-Violet J137-7 · Q92
Row 4
Red-Yellow J133-5 · Q87

Parts

  • Installed LED 555 Green Frosted
  • Bulb #555 24-8768
  • Assembly A-12887-B

Location

Related

Service log

 

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Service notes: In the lamp matrix at column 7 (driver Q92, J137-7) and row 4 (driver Q87, J133-5). One dark lamp is the #555 bulb (24-8768) or its socket; a whole column or row dark is the driver transistor or the J137/J133 connector, not the bulbs. Find it in T.8 Single Lamp Test. With LEDs, a faint glow on lamps that should be off is matrix ghosting: the ghost-busting ROM for this game or non-ghosting LEDs. A4 Lamps, flashers and GI