TM 1-1520-238-T-4
6170
Change 4
687.
VIB GRBX INDICATOR LIGHTS
687
Tools:
Nomenclature
Part Number
Tool Kit, Electrical
SC518099CLA06
Repairers
Multimeter, Digital
AN/PSM-45
Personnel Required:
68X
Armament/Electrical Systems Repairer
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. Check pilot caution/warning panel VIB GRBX
indicator.
Is indicator lighted?
YES
Go to step 2.
NO
Replace rotor
balance signal processor
(TM 1-1520-238-23).
If problem persists, replace
intermediate gearbox
(TM 1-1520-238-23).
If problem persists, replace
tail rotor gearbox
(TM 1-1520-238-23).
2. Detach P129.
Does VIB GRBX indicator remain lighted?
YES
Go to step 3.
NO
Replace rotor
balance signal processor
(TM 1-1520-238-23).
3. Detach P18. Check for short between P129E
and ground.
Does short exist?
YES
Repair shorted wire.
Go to paragraph 681.
NO
Replace pilot caution/warning
panel (TM 1-1520-238-23).
