Advanced-Level Troubleshooting - Furuno 1815 Operator's Manual

7. MAINTENANCE, TROUBLESHOOTING
7.5

Advanced-level Troubleshooting

This section provides hardware and software troubleshooting procedures for the qual-
ified serviceman.
Problem
Power cannot be
turned on.
Brilliance adjusted
but no picture.
Antenna not rotat-
ing.
Gain is maximum
and sea clutter is
minimum. Marks
and indications ap-
pear but no noise
or echo.
Marks, indications
and noise appear
but echoes do not.
(Own ship is not
shown.)
The picture has
"frozen".
Radar is correctly
tuned but sensitivi-
ty is poor.
Range picture
does not change
when range is
changed.
Range rings are
not displayed.
7-4
Advanced-level troubleshooting
Probable cause or check
points
1) Mains voltage/polarity
2) Power supply board
1) MAIN Board
1) Antenna drive mechanism
1) Signal cable between an-
tenna and display unit
2) IF-SPU Board
1) Magnetron
2) MD-PWR Board
3) IF-SPU Board
1) Heading sensor inside an-
tenna unit
2) MAIN board
1) Dirt on radiator face
2) Deteriorated magnetron
3) Detuned MIC
1) MAIN Board
2) SPU board
1) Adjust their brilliance on the
[Brill/Color] menu.
2) MAIN Board
Remedy
1) Correct the wiring and input
voltage.
2) Replace power supply
board.
1) Replace the MAIN board.
1) Replace the antenna drive
mechanism.
1) Check continuity and isola-
tion of coaxial cable.
2) Replace IF-SPU Board.
Check coax line MIC and IF-
SPU board for tight connec-
tion. If connection is good,
replace IF-SPU board.
1) Select max. range, then
check magnetron current. If
current is below rated value,
replace magnetron.
2) Replace MD-PWR Board.
3) Replace IF-SPU board.
1) Check connection between
IF-SPU board and heading
sensor.
2) Replace MAIN board.
3) Turn radar off and on.
1) Clean the radiator.
2) Check the magnetron cur-
rent with radar on max.
range. If the current is below
normal, magnetron may be
defective. Replace the mag-
netron.
3) Restore default tuning. Re-
place MIC.
1) Replace MAIN Board.
2) Turn radar off and on.
1) Replace associated circuit
board if unsuccessful.
2) Replace MAIN Board.