Service Manual

34
Rx Section
Start
No receive
Normal power
supply of receiving
circuit?
Yes
No
Check Rx power
supply circuit
Rx squelch level is
correct?
Normal Rx LED?
Rx frequency is
correct?
Rx signalling is
correct?
Speaker works
well?
Normal audio
power amplifier?
Normal Volume
Selector knob?
P29 and P25, which are pins of
baseband processor ICU200,
output signals well?
Normal
demodulators?
Normal IF and
mixing circuits?
Normal RF mixing
circuit?
Change Rx
frequency
Change Rx
squelch level
Replace Rx
LED D601
Change Rx
signalling
Replace the
speaker
Check audio
power amplifier
circuit
Replace the
Volume
Selector knob
Check audio
processor
circuit
Check and
replace CD300
and CF300
Check Q105,
U200 (P12,P21)
and XF1
Check local
oscillator circuit
Q501
Check BPF
circuit Q500
Check antenna
connection
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
Completed
Yes
Yes
No
No
No
No
No
No
No