Motorola GP344 - Page 166

2-4 TROUBLESHOOTING CHARTS
Bad SINAD
Bad 20dB Quieting
No Recovered Audio
START
Audio at
pin 8 of
U3220?
Check Controller
(in the case of no audio)
OR ELSE go to “B”
Yes
No
Spray or inject 44.85MHz
into XTAL Filter Y3200
Audio heard?
B
Yes
No
Check 2nd LO
(44.395MHz) at C3274
LO Present?
B
Yes
Voltages
ok?
Biasing ok?
Check circuitry
around U3220.
Replace U3220
if defect
No
No
A
Yes
Check Q3200 bias
for faults.
Replace Q3200.
Go to B
Yes
No
Check voltages on
U3220
Check circuitry
around Y3202.
Replace Y3202
if defect
Figure 2-3 Troubleshooting Chart for Receiver (PCB 8415533H02) (Sheet 1 of 2)