TM 1–1520–238–T–3
21–2
Change 4
MULTIPLEX READ CODE INTERPRETATIONS
21–1 SIGNAL NAME: ORT VIDEO RECORD SWITCH (ACY) RECORD SW (ACZ)
MEMORY LOCATION: 000441
MEMORY DATA BIT(S): 6 (BINARY)
CONDITION: (None)
SIGNAL FUNCTION: Enables video recording.
REMARKS: From optical relay tube (ORT) through CPG MRTU Type III to FCC.
PASS: If fifth digit displayed on HOD is 0, 1, 4, or 5, go to paragraph 21–2.
FAIL: Location of fault: ORT righthand grip, wiring from ORT righthand grip to CPG MRTU Type III,
CPG MRTU Type III. Troubleshoot wiring to isolate fault (TM 1–1270–476–T).
21–2 SIGNAL NAME: VIDEO RECORDER CONTROL PANEL ON/ OFF (ACY)
VCR ON OFF IND (ACZ)
MEMORY LOCATION: 000440
MEMORY DATA BIT(S): 9 (BINARY)
CONDITION: (None)
SIGNAL FUNCTION: Monitors power to video recorder.
REMARKS: From video recorder control panel through CPG MRTU Type III to FCC.
PASS: If fourth digit displayed on heads out display (HOD) is 2, 3, 5, or 7, go to paragraph 21–3.
FAIL: Location of fault: FC RCDR circuit breaker, wiring from FC RCDR circuit breaker to video
recorder, wiring from video recorder to video recorder control panel, CPG transformer rectifier,
wiring from CPG transformer rectifier to video recorder control panel, video recorder control
panel. Troubleshoot wiring to isolate fault (TM 11–1520–238–23–2).
