Troubleshooting Flow Chart For Receiver (Models With Pcb 8486458Z03) (Sheet 1 Of 2) - Motorola GP Series Detailed Service Manual

2-4
4.0 Troubleshooting Flow Chart for Receiver (Models with PCB
8486458Z03) (Sheet 1 of 2)
B
B
Check circuitry
around U301.
Replace U301 if
defect
START
Bad SINAD
Bad 20dB Quieting
No Recovered Audio
Audio at pin 8
of U301?
No
Spray or inject 1st IF 44.85
MHz into
XTAL Filter
Yes
Audio heard?
No
Check 2nd LO signal
44.395 MHz at C367
Yes
Signal
Present?
No
Check voltages on
U301
No
Voltages
ok?
Yes
Check Controller
Replace Q302.
Check circuitry
Yes
around Y300.
Replace Y300 if
defect
TROUBLESHOOTING CHARTS
A
Check Q302 bias
circuitry for faults.
Rotate Freq. Knob
No
Biasing ok?
Yes
Go to B