Except Those With Pcb 8486473Z04; Troubleshooting Flow Chart For Receiver, For All Models Except Those With Pcb 8486473Z04 (Sheet 1 Of 2); Troubleshooting Flow Chart For Receiver, For All Models - Motorola HT Series Service Manual

Maintenance: VHF Troubleshooting Charts

8.12.3 Troubleshooting Flow Chart for Receiver, for all models

except those with PCB 8486473Z04 (Sheet 1 of 2)
B
B
Check FGU
START
Bad SINAD
Bad 20dB Quieting
No Recovered Audio
Audio at pin
27 of U3220?
No
Spray of inject 1st IF into
XTAL Filter
IF Freq: 45.1MHz
Yes
Audio heard?
No
Check 2nd LO Control
Voltage at C3279
Yes
VCO locked?
No
16.8 MHz
No
check at pin
21 U3220?
Yes
A
Yes
Check Controller
Check controller.
Before replacing U3220, check 2nd
VCO Q3270. Check VCO O/P level,
A
Check Q3270 bias
circuitry for faults.
Rotate Freq. Knob
No
Activity on
U3220 sel
pin?
Yes
C3272, C3273.
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