Furuno BB FAR28x7 - Manual (Page 240)

6. MAINTENANCE, TROUBLESHOOTING
6-6
6.7 Advanced-level Troubleshooting
This paragraph describes how to cure hardware and software troubles which
should be carried out by qualified service personnel.
Note: This radar equipment contains complex modules in which fault diagnosis
and repair down to component level are not practicable by users.
Advanced troubleshooting
Problem Probable causes or check
points Remedy
Power turned on but radar
does not operate at all 1) Blown fuse.
2) Mains voltage/polarity
3) Power supply board
1) Replace blown fuse.
2) Correct wiring and input voltage.
3) Replace power supply board.
Brilliance adjusted but no
picture SPU board Replace SPU board.
Antenna not rotating 1) Antenna drive
mechanism
2) Defective antenna drive
motor relay (thermal
relay K2, 200/220/380,
440/100 VAC)
1) Replace antenna drive mechanism.
2) Press relay reset button.
Data and marks not
displayed in Transmit
status SPU board Replace SPU board.
Adjust GAIN with A/C SEA
set at minimum. Marks and
indications appear but no
noise or echo 1) IF amplifier
2) Signal cable between
antenna and processor
unit
3) Video amplifier board
1) Replace IF amplifier.
2) Check continuously and isolation of
coaxial cable.
Note: Disconnect the plug and lugs
at both ends of coaxial cable before
checking it by ohmmeter.
3) Check video coax line for secure
connection. If connection is good,
replace SPU board.
(Continued on next page)