Motorola GP344 - Troubleshooting Chart for Receiver (Sheet 1 of 2); Troubleshooting Chart for Receiver (Sheet 2 of 2)

2-2 TROUBLESHOOTING CHARTS
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?
Activity on
U301 sel
pin?
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
Figure 2-1 Troubleshooting Chart for Receiver (Sheet 1 of 2)