Simrad AP27 Manual page 121

Display readout
Shallow water
(Only if AP25 is
part of the
system)
Compass data
missing
Rudder feedback
failure (autopilot
operates on
simulated
feedback)
Rudder response
failure
Rudder too slow
20221586B
Probable fault
The depth is inside
the set limit or outside
the range.
Depth data is missing.
No data from selected
compass.
Rudder feedback
signal missing or
erratic
No response to rudder
command
Excessive load on
steering gear. Air in
hydraulic system.
Insufficient drive unit
capacity.
Recommended action
1. Carefully observe the actual
depth.
2. Adjust the alarm limit if not
hazardous.
3. Steer to safe depth, the alarm
will reset automatically.
4. Turn off the shallow alarm if
depth data is missing.
1. If more that one compass is
connected to the system, refer to
the User Setup2/Source select
menu to select a different
compass.
2. Make a source update if no
compass is available.
3. Check connections.
4. Replace compass PCB (Note: Do
not cut cables. There are screw
terminals inside).
1. Check all connections.
2. Check the alignment as per the
installation instructions
3. Replace rudder feedback unit.
1. Check all connections
2. Check Rudder FB transmission
link.
3. Check drive unit motor/brushes.
4. Replace the Autopilot Computer
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 bigger pump unit.
Trouble shooting
119