TM 5-6675-250-20
2.10. TROUBLESHOOTING (Continued)
T a b l e 2 - 3 . T r o u b l e s h o o t i n g ( C o n t i n u e d)
M A L F U N C T I O N
TEST OR INSPECTION
CORRECTIVE ACTION
GYROSCOPIC REFERENCE UNIT (GRU) (Continued)
4 . C A G E - U N C A G E C O N T R O L I N O P E R A T I V E.
Step 1.
Check for loose knob.
Tighten set screws (1 and 2)
in knob (3).
Step 2. Check for defective control.
a. Replace existing GRU with one that is operable. If the system
operates correctly with new GRU, this indicates original GRU was defec-
tive.
2-25
