Motorola GP Series Service Information page 27

Troubleshooting Flow Chart for Receiver, for models with PCB 8486473Z04 (Sheet 1 of 2)
2.0 Troubleshooting Flow Chart for Receiver, for models with PCB
8486473Z04 (Sheet 1 of 2)
B
B
Check circuitry
around U3220.
Replace U3220
if defect
START
Bad SINAD
Bad 20dB Quieting
No Recovered Audio
Audio at pin
8 of U3220?
No
Spray or inject 44.85MHz
into XTAL Filter Y3200
Yes
Audio heard?
No
Check 2nd LO
(44.395MHz) at C3274
Yes
LO Present?
No
Check voltages on
U3220
No
Voltages
ok?
Check Controller
Yes
(in the case of no audio)
OR ELSE go to "B"
Replace Q3200.
Check circuitry
Yes
around Y3202.
Replace Y3202
if defect
A
Check Q3200 bias
for faults.
No
Biasing ok?
Yes
Go to B
3-3