Furuno FS-1503 - 5.3 Troubleshooting

5-6
5.3 Troubleshooting
Table 5-1 Troubleshooting Guide List
Symptom Possible Cause/Test Remedy
1 Brown in-line fuse (30A). Replace fuse.
2 Overvoltage protector (17 V) activated.
Check power supply for
13.6 V
±
15 %.
3
Defective power switch. Disconnect power
connector, check between J1 #1 and #2 on
PA/FIL board for continuity.
Replace switch.
1
No power being
supplied
4
Defective SW REG board (optional).
Measure voltage between J2 #1 and #3 for
12 V (input), and between J3 #1 and #3 for
12 V (output).
If no input, replace PA/FIL
board. If no output, replace
SW REG board.
1
When getting into TX mode. Defective
relay K1. Breaker F2 on PA/FIL board
trips.
Replace PA/FIL board.
2 Defective PA Transistor.
Replace PA Transistor, or
PA/FIL board.
2
Power is shut
down.
3 When connecting BK line.
Check BK lines for correct
wiring.
3 LCD blinks. 1
UNLOCK signal is detected; defective
PLL.
Replace TX/RX board.
4
Nothing on LCD
display
1
If 12 V is supplied to PA, F1 (4A) on
PA/FIL board trips.
Check J2 (12 V line) on
PA/FIL board for overload.
5
LCD display is
freezed, or
abnormal.
1
Loose connection on PCB. Defective flat
cable on CPU board.
Check connections. Replace
CPU board.
1
Specific key does not work. (Carry out
self-test.)
6 No key response
2
All keys do not work. CR1 on CPU board
does not blink.
Replace CPU board.
1 Carry out self-test.
If cannot, replace COUP
board.
2
If TUNE error appears immediately after
TX, no RF signal is input to antenna cou-
pler.
⋅
Check coaxial cable between
main unit and antenna cou-
pler for discontinuity.
⋅
Check transmitter circuit in
main unit.
⋅
Check TUNE power data for
40 (standard).
3
If antenna coupler does not start tuning,
control circuit is defective.
⋅
Check system setting 9920.
⋅
Check control signal lines
connected between main unit
and antenna coupler
4
If TUNE error occurs on specific band,
antenna and/or grounding is abnormal.
Check antenna and ground
wire connection. If OK, try to
change antenna length.
5
If tuning is unstable on specific band, an-
tenna and/or grounding is abnormal, or
matching relay in antenna coupler is de-
fective.
⋅
Check antenna and ground
wire connection. If OK, try
to change antenna length.
⋅
Replace COUP board.
7 TUNE error
6
If frequency range in which TUNE error
occurs is the same as that of a TX filter,
TX FIL circuit is defective.
Replace PA/FIL board.