TROUBLESHOOTING
SYMPTOM
POSSIBLE CAUSE
REMEDY
System dead
- power off
- fuse blown
- DC power input polarity reversed
- turn on power
- replace fuse
- reverse connection
Erratic operation
- follow-up pot of FFU or controller
potentiometer defective
- check follow-up and
controller potentiometer
- meter output voltage, replace
if necessary
Rudder hunts back
and forth
- deadband control in Model 7173-KAS
Amplifier incorrectly adjusted
- reduce gain by turning
counter-clockwise
Rudder goes to a
hardover position
- defective potentiometer
- damaged cable
- sticky solenoid valve or relay
- loose follow-up linkages
- solenoid wires reversed
- feedback wires reversed
- replace
- repair
- repair or replace
- repair
- reverse wires
- reverse wires
Rudder does not travel
same number of
degrees hardover to
hardover
- control potentiometer not centered
- feedback unit or potentiometer not
centered
- meter output voltage or
resistance
- meter output voltage or
resistance
LED Lights and Output Indicator Information
If “L1” LED light is ON, then Solenoid “A” output is active.
If “L2” LED light is ON, then Solenoid “B” output is active.
If “L3” LED light is ON, then Solenoid “C” output is active.
If “L4” LED light is ON, then Solenoid “D” output is active.
L1 and L2 continuously ON - U1 damaged
- replace
L3 and L4 continuously ON – U2 damaged
- replace
If “L5” LED light is ON, then the “Alarm Output” will be active to indicate control or feedback
potentiometer failure or wire break. The 7173-KAS will fail in mode upon potentiometer or wire
break failure.
