TM 1-1520-238-T-5
8–112
8–44.
CPG ENG–RTR RPM% – DOES NOT INDICATE FULL SCALE OR VERTICAL SCALE
8–44
INDICATORS HAVE EVERY OTHER LAMP NOT LIGHTED (HELICOPTERS WITH CPG
DIM/TEST PANEL INSTALLED)
Tools:
Nomenclature
Part Number
Tool Kit, Electrical
SC518099CLA06
Repairer’s
Multimeter, Digital
AN/PSM-45
Personnel Required:
68X
Armament/Electrical Systems Repairer (2)
References:
TM 1-1520-238-23
WARNING
Turn off power before detaching or
attaching wires and connectors. High
current 28 VDC or 115 VAC is present.
Failure to do so could result in death or
serious injury.
1. On CPG dim/test panel, hold
DGT OFF/NORM/TST switch to TST. Check for
short between P73–17 and ground.
Does short exist?
YES
Go to step 2.
NO
Repair open wire between
P73–17 and P73–SP1.
Go to paragraph 8–10.
2. Check for 2 to 5 VDC at P73–7 and P73–8.
Is voltage present?
YES
Go to step 3.
NO
Go to step 6.
3. Check for:
–8 VDC at P73–13,
8 VDC at P73–14.
Are voltages present?
YES
Go to step 4.
NO
Go to step 5.
4. Check for open between:
P73–9 and GS245–C,
P73–10 and GS245–D,
P73–11 and GS255–A.
Does open exist?
YES
Repair open wire.
Go to paragraph 8–10.
NO
Replace CPG ENG–RTR
RPM% indicator
(TM 1-1520-238-23).
5. Check for open between:
P73–13 and P400–10,
P73–14 and P400–2.
Does open exist?
YES
Repair open wire.
Go to paragraph 8–10.
NO
Replace SDC
(TM 1-1520-238-23).
6. Check for open between:
P73–7 and P1093–2,
P73–8 and P1093–5.
Does open exist?
YES
Repair open wire.
Go to paragraph 8–10.
NO
Replace CPG ENG INST
dimmer power supply.
(TM 1-1520-238-23).
END OF TASK
