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§.2 Troubleshooting
Guide
Troubleshooting Step 1:|/No power.
Major Causes:
0 Blown fuse (F301)
0 Vessel battery voltage too high or too low
0 Broken connections in power cable or short circuit
0 Failure on power supply board
Checks and Repairs
1)
Check fuse F301 and replace it (104A) if it has blown.
2) — Check the input supply voltage.
Check Point
Rating
Between power cable connector pins 1, 2
10.8 to 42 VDC
Between CN351 pins 1, 2
10.8 to 42 VDC
3)
Disconnect the signal cable connector and switch on the power. If the power does not come on or if
the fuse "blows," the problem may lie with the power supply board.
4)
If power is supplied when the signal cable connector is disconnected, the overload protector in
the antenna unit has been tripped. Check out the antenna unit following the troubleshooting
procedure.
5)
if the voltage between CN303 pins 1 to 4 is normal (10.8 to 42 VDC), check the voltage between the
pins below:
Check point
Raiting
CN301
Pins 7 and 6: Approx.
+12VDC
Pins 9 and 6: Approx.
-12VDC
Pins 8 and 6: Approx.
+5VDC
Replace the power supply board if output voltage is not supplied.
Troubleshooting Step 2:|"NO HD" or "NO BP" appears.
Possible Causes
Trouble with the connections of the signal cable connectors (looseness, etc.)
Trouble with the CN2 connections on the processor board (looseness, etc.)
Failure of motor inside antenna unit
Failure of antenna rotation mechanism
Missing magnet for heading detection of antenna
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Checks and Repairs
ce)
When both "NO HD" and "NO BP" appear, improper connection or a motor failure may be to blame.
Check for looseness in the signal cable connections and connector CN2 connections on the
processor board.
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—— Switch off the power and remove the antenna radome cover.
re)
When only "NO HD" appears, check whether the magnet for detecting the heading is missing and
also check the connector CN804 connection.
(See Fig. 53)
re)
Try rotating the antenna by hand. If it does not turn smoothly, check for damage to the gears and
replace if necessary.
ce)
if the antenna rotates smoothly by hand, a failure in the motor or motor drive section may be to
blame.
ce)
Check the voltage across pins 1 and 2 of connector CN801 on the modulator board.
If the voltage
is about 5 VDC, the motor is defective and should be replaced.
if the voltage is not observed, check the voltage across pins 5 and 6 of connector CN803 on the
modulator board. If it is about 12V, the modulator board is defective and should be replaced.
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