Furuno FAR-1416 Operator's Manual page 193

Problem
Picture not updated or
picture freeze-up
Incorrect orientation of
picture
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 (IR level is
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
Trackball control unit is
not responsed
Possible cause
1) Bearing signal generator
board (in antenna unit)
2) SPU board
3) Video freeze-up
1) Terminal board: RFTB/
RTB (inside transceiver
unit) or FRP_TB board
(inside display unit)
2) SPU board
SPU board
1) Deteriorated magnetron
2) Detuned MIC
3) Dirt on radiator face
4) Second trace echo rejec-
tion is ON
1) Defective range key
2) SPU board
3) Video freeze up
SPU board
SPU board
1) Adjust the brilliance of
range rings on the BRILL
menu to see if intensity is
increased
2) SPU 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 control unit
7. MAINTENANCE, TROUBLESHOOTING
Remedy
1) Check the connection of signal cables.
2) Replace SPU board.
3) Turn the radar off, then on.
If the message "HEADLINE" appears in or-
ange letters inside the alert box, the head-
ing signal is lost or interrupted. Check the
heading line signal cable and terminal
board connections. If there is no problem
with cables or connections, replace the
SPU board.
Replace SPU board.
1) With the radar transmitting on 48 nm
range, check magnetron current. If cur-
rent 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) Disable the second-trace echo rejector
referring to section 1.30.
1) Adjust the range with the control unit,
or the [RANGE] box several times. If
unsuccessful, replacement of control
unit 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 SPU 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 1.12, select TM
orientation mode.
2) Enter correct own ship speed referring
to section 1.15.
3) Make sure that speed and compass in-
puts are accurate.
Adjust A/C SEA and A/C RAIN referring to
section 1.19 and section 1.20.
Replace trackball control unit.
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