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
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
Figure 2-1 Troubleshooting Chart for Receiver (Sheet 1 of 2)
Yes
Check Controller
Check controller.
TROUBLESHOOTING CHARTS
A
Check Q3270 bias
circuitry for faults.
Rotate Freq. Knob
No
Activity on
U3220 sel
pin?
Yes
Before replacing U3220, check 2nd
VCO Q3270. Check VCO O/P level,
C3272, C3273.