Simrad AP50 Operator's Manual page 52

Simrad AP50 Autopilot
Display readout
No rudder
response
(The system will
switch to Stby
mode)
Rudder too slow
Rudder test failed
46
Probable fault
− Steering gear not
operative
− Broken connection
− Missing power
− Rudder feedback not
moving with rudder
Note!
It is recommended to try to
locate the fault to either the
rudder drive (command
signal, steering gear,
pump, bypass valve, clutch
etc.) or the rudder
feedback by giving
NFU/FU commands on the
control unit and observing
the rudder response on the
feedback readout of the
same unit.
− Defective electronics
Excessive load on steering
gear, air in the hydraulic
system or insufficient drive
unit capacity.
The following conditions
may exist:
a) Rudder feedback failure.
b) J50 current overload.
c) Bypass/clutch overload.
Rudder moves in only one
direction
a) Poor connection to one
of the solenoids
(continuously running
pump).
b) Faulty Power PCB in
junction unit.
Recommended action
Note!
If rudder control is from an AD50 or
a JD5X, refer to the troubleshooting
section in the AD50 manual or the
AP50 Plus Installation Manual.
1. Check all connections.
2. Check Rudder FB
transmission link, steering
gear, and change over
switches.
3. Check the drive unit motor/
brushes and bypass
valve/clutch.
For solenoid drive:
4. Check LEDs for command
from galvanic isolated
solenoid electronics (Refer to
the AP50 Installation Manual,
Junction Unit terminals).
5. Replace the junction unit
Power PCB.
6. Check the jumper switch (S1)
setting on J50 Power PCB.
1. Look for mechanical
obstructions at the
rudder/tiller/quadrant. Check
the back drive force.
2. Bleed the hydraulic system.
3. Replace with a bigger pump
unit.
Refer to the recommended actions
for the specific probable faults.
a) Check the connections
b) Replace the junction unit
Power PCB
20221032 / E