Furuno FCR-2107 Operator's Manual page 421

Problem
Antenna not rotating
Data and marks not displayed in
Transmit status
Adjust GAIN with A/C SEA set
at minimum. Marks and
indications appear but no noise
or echo
Marks, indications and noise
appear but no echo
(Transmission leak representing
own ship position is absent)
Picture not updated or picture
freeze-up
Incorrect orientation of picture
Incorrect orientation of picture
Cannot operate radar from on-
screen boxes
Probable causes or
check points
1) Antenna drive mechanism
2) Defective antenna drive motor
relay (thermal relay K2,
200/220/380, 440/100 VAC)
SPU board
1) IF amplifier
2) Signal cable between antenna
and processor
unit
3) Video amplifier board
1) TX fuse
2) Magnetron
3) Modulator board
4) SPU board
1) Bearing signal generator board
(in antenna unit)
2) SPU board
3) Video freeze-up
1) SPU board
2) Gyro interface
1) SPU board
2) Gyro interface
SPU Board
22. Maintenance and Troubleshooting
Remedy
1) Replace antenna drive mechanism.
2) Press relay reset button.
Replace SPU 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.
1) If fuse is blown, replace it. If it blows
again, the modulator or associated
circuit may be defective.
2) Check magnetron current.
Replace magnetron.
3) Replace modulator board.
4) Replace SPU board.
1) Check the connection of signal cables.
2) Replace SPU board.
3) Turn off and on the radar.
1) The message GYRO appears when the
heading pulse is not received during standby.
2) Replace the gyro interface.
1) The message GYRO appears when the
heading pulse is not received during standby.
2) Replace the gyro interface.
Replace SPU Board.
22-9