Motorola Pro Series Elite - Troubleshooting Flow Chart for Receiver (Sheet 1 of 2)

UHF (Band 1 and Band 2) Troubleshooting Charts 3-17
Bad SINAD
Bad 20dB Quieting
No Recovered Audio
START
Audio at pin 27 of
U301?
Check Controller
Yes
No
Spray of inject 1st IF into XTAL Filter
IF Freq: 45.1MHz
Audio heard?
B
Yes
No
Check 2nd LO Control Voltage at
C363
VCO locked?
B
Yes
16.8 MHz check at
pin 22 U301?
Check FGU
No
No
A
A
Yes
Check Q320 bias circuitry
for faults.
Rotate Freq. Knob
Check controller.
Before replacing U301, check 2nd VCO Q320. Check
VCO O/P level, C351, C352.
Yes
No
Troubleshooting Flow Chart for Receiver (Sheet 1 of 2)
Activity on U301 sel
pin?