Furuno FAR-2218 Operator's Manual page 239

Problem
Cannot operate radar
from on-screen boxes
Radar is properly tuned
but poor sensitivity
Range changed but ra-
dar picture not chang-
ing
Interference rejector is
inoperative (interfer-
ence rejection level not
displayed)
Echo stretch is ineffec-
tive (neither ES1, ES2
nor ES3 is displayed)
Range rings are not
displayed
Poor discrimination in
range
True motion orientation
not working correctly
Target not tracked cor-
rectly
Buttons on trackball
module operated but
no response
Picture is not updated
with each sweep.
Possible cause
MAIN board - inside the Pro-
cessor unit.
1) Deteriorated magnetron
2) Detuned MIC
3) Dirt on radiator face
4) Water ingress to the
waveguide or other feed-
er line
5) Second trace echo rejec-
tion is ON
1) Defective range key
2) SPU board inside the an-
tenna.
3) Video freeze up
SPU board inside the anten-
na.
SPU board inside the anten-
na.
1) Adjust the brilliance of
range rings on the BRILL
menu to see if intensity is
increased
2) MAIN board
Sea clutter control not func-
tioning properly
1) Incorrect menu setting
2) Speed entry incorrect
3) TM display inaccurate
Poor definition of targets in
sea clutter
Trackball module
Motor/gears
6. MAINTENANCE, TROUBLESHOOTING
Remedy
Replace MAIN board.
1) With the radar transmitting on 48 nm
range, check magnetron current. If
current is below normal, magnetron
may be defective. Replace it.
2) Check MIC detecting current. If it is be-
low normal value, MIC may have be-
come detuned. MIC must be tuned.
3) Clean the radiator surface.
4) Remove water from the feeder line.
5) Disable the second-trace echo rejector
referring to section 1.29.
1) Adjust the range with the control unit,
or the [RANGE] box several times. If
unsuccessful, replacement of keypad
may be required.
2) Replace SPU board.
3) Turn off and on radar.
Replace SPU board.
Replace SPU board.
1) Replace associated circuit board if un-
successful.
2) Replace MAIN board.
Improper setting of A/C SEA. If A/C SEA is
seen only at very close range, suspect in-
accurate frequency of reference oscillator.
1) Referring to section 1.30, select TM
orientation mode.
2) Enter correct own ship speed referring
to section 1.12.
3) Make sure that speed and compass in-
puts are accurate.
Adjust A/C SEA and A/C RAIN referring to
section 1.20 and section 1.21.
Replace trackball module.
Check the motor and gears. Replace if
worn.
6-7