Furuno FR-2155, Service Manual

Page: 102 / 152

5-10
Symptom: Poor sensitivity
FR2155-SME-68
Flow chart 8
Less than
1000 hrs ?
OK
No echo; poor
sensitivity.
No echo (White noise appears)
Check TOTAL ON
TIME/TOTAL TX TIME.
Rating ?
OK
Check if display unit
outputs TX trigger.
(DJ-1 #4)
DJ-1#7 is normal ?
OK
Check TUNE voltage
output from display unit.
(Switch from ST-BY to TX)
Manual Tune Voltage :
about 2 V to 32 V
TUNE IND value in manual mode ;
about 1 to 3 V
In manual mode, rotate
TUNE VR.
NG
Poor sensitivity
NG
(No TX trigger)
Faulty pcb 03P9253.
NG
Faulty pcb 03P9253.
0V
approx. 12V
Replace
magnetron.
To 1)
(page 5-11)
OK
Faulty pcb 03P9253.
NG
0V
approx. -4V
TUNE IND in
self-test result ?
OK
To 2)
(page 5-12)
NG
OK
NG
Manual tuning ?
Check maximum gain is
obtained with maximum
tuning indication.
OK
NG
OK ?
Defective IF amp.
Defective MIC
OK
NG
Perform Tuning
Initialization. Defective IF amp.,
MIC, or SPU board.
Defective EEPROM,
Defective back-up ckt
Check input video
signal to INT Board,
TP1 & TP6.
OK?
Defective IF AMP (03P6734C)