Troubleshooting Chart For Receiver (Sheet 1 Of 2); Troubleshooting Chart For Receiver (Sheet 2 Of 2) - Motorola GP344 Detailed Service Manual

2-2
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
Figure 2-1 Troubleshooting Chart for Receiver (Sheet 1 of 2)
Yes
Check Controller
Check controller.
VCO Q320. Check VCO O/P level,
TROUBLESHOOTING CHARTS
A
Check Q320 bias
circuitry for faults.
Rotate Freq. Knob
No
Activity on
U301 sel
pin?
Yes
Before replacing U301, check 2nd
C351, C352.