Furuno FS-1503, Service Manual

Page: 76 / 136

5-7
Symptom Possible Remedy
1-1
Carry out self-test. If TE is NG, TX signal
is not output from TX/RX board.
Replace TX/RX board.
1-2
Carry out self-test. If TP is NG, TX signal
is not output from PA/FIL board.
Replace PA/FIL board.
2
Carry out self-test. If TE is good and no
signal is emitted on all bands, PA transistor
is defective.
Replace PA/FIL board or PA
transmitter(s).
8
Abnormal
transmission
3
Carry out self-test. If TE is good and no
signal is emitted on specific band, power
data is incorrect.
Check power data for 220
(standard).
1
Carry out self-test. If R is NG, receiver
circuit on TX/RX board is defective.
Replace TX/RX board.
2-1
If sensitivity is low on all bands, check
main unit with antenna coupler discon-
nected. If main unit is OK, antenna coupler
or antenna is defective.
Check antenna. Replace
COUP board.
2-2
If sensitivity is low on all bands, check
main unit with antenna coupler discon-
nected. If main unit is NG, RX RF circuit
is defective.
Replace TX/RX board.
2-3
If sensitivity is low on specific band, FIL
circuit on PA/FIL board is defective.
Replace PA/FIL board.
3
Sensitivity is very low on less than 1.6
MHz. Check jumper setting of J8/J9
for 2: 0.1 to 30 MHz.
4
No receiving sound on specific emission
mode (Defective demodulation circuit)
Replace TX/RX board.
5 No TLX receiving sound
IF FIL (0.4 k) is not fitted on
TX/RX board.
6
No sound from either internal or external
speaker
Replace the speaker.
7
No receiving sound from both internal and
external speakers (Receiver AF circuit U15
is defective.)
Replace TX/RX board.
9 Abnormal reception
8 Heavy external noise.
Find noise source by turning
on other equipments one at a
time.
RF meter reading vs output power
RF meter reading 0 1 2 3 4 5 6 7 8 9 10 11
Output power (W) 0 + 2 10 15 30 40 50 60 67 72 75 <