Operating instructions

Section 7
TROUBLESHOOTING CHARTS
1.0 800/900 Band Troubleshooting Charts
START
Bad SINAD
Bad 20db Quieting
No Recovered Audio
Check Controller
Spray of inject 1
st
IF
into XTAL Filter
IF Freq:
Check 2
nd
LO Control
Voltage at TP601
Audio
heard?
VCO Locked?
Check 18MHz at pin 19
& 20 U600, Check
16.8MHz at pin 35
U600?
B
B
A
Check Q602 bias
circuitry for faults
Rotate Freq. Knob
Activity on
U600 CE pin?
Before replacing U600,
check 2
nd
VCO Q602, check
VCO o/
p
level at C606
A
No
Yes
Yes
No
Check FGU
Yes
No
Yes
No
73.35MHz
(800/900)
Troubleshooting Flow Chart for Receiver
(Sheet 1 of 2)