Troubleshooting Flow Chart For Receiver For All Models Except; Pcb 8486458Z03 (Sheet 1 Of 2) - Motorola HT Series Service Manual

Maintenance: UHF Band 1 Troubleshooting Charts

8.10.3 Troubleshooting Flow Chart for Receiver for all models except

PCB 8486458Z03 (Sheet 1 of 2)

B
B
Check FGU
START
Bad SINAD
Bad 20dB Quieting
No Recovered Audio
Audio at pin
27 of U301?
No
Spray of inject 1st IF into
XTAL Filter
IF Freq: 45.1MHz
Yes
Audio heard?
No
Check 2nd LO Control
Voltage at C363
Yes
VCO locked?
No
16.8 MHz
No
check at pin
22 U301?
Yes
A
Yes
Check Controller
Check controller.
Before replacing U301, check 2nd
VCO Q320. Check VCO O/P level,
A
Check Q320 bias
circuitry for faults.
Rotate Freq. Knob
No
Activity on
U301 sel pin?
Yes
C351, C352.
8-11