TM 1-1520-238-T-4
6–103
6–41.
VIB GRBX INDICATOR – LIGHTS WITH ELECTRICAL POWER APPLIED AND ALL
6–41
POWER PLANTS OFF
Tools:
Nomenclature
Part Number
Tool Kit, Electrical
SC518099CLA06
Repairer’s
Multimeter, Digital
AN/PSM-45
Personnel Required:
68X
Armament/Electrical Systems Repairer
References:
TM 1-1520-238-T-6
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. Detach P129.
Does VIB GRBX indicator remain lighted?
YES
Go to step 3.
NO
Go to step 2.
2. Attach P129. Detach P128.
Does VIB GRBX indicator remain lighted?
YES
Replace rotor balance signal
processor (TM 1-1520-238-23).
NO
Go to step 4.
3. Check for short between P18–31 and ground.
Does short exist?
YES
Repair shorted wire.
Go to paragraph 6–12.
NO
Refer to TM 1-1520-238-T-6 to
troubleshoot the pilot
caution/warning system.
4. Attach P128. Detach P58.
Does VIB GRBX indicator remain lighted?
YES
Go to step 5.
NO
Replace TGB accelerometer
(TM 1-1520-238-23).
5. Detach P59.
Does VIB GRBX indicator remain lighted?
YES
Detach P128 and P56. Check
for shorted wire between:
P58–A and ground,
P58–B and ground,
P59–A and ground,
P59–B and ground.
Repair shorted wire.
Go to paragraph 6–12.
NO
Replace IGB accelerometer
(TM 1-1520-238-23).
END OF TASK
