Motorola 6864115B62-C

3-2 Low Band TROUBLESHOOTING CHARTS
2.0 Troubleshooting Flow Chart for Receiver
(Sheet 1 of 2)
Check
circuitry
around U1103.
Replace U1103
if defect.
Check circuitry
around U1103.
Replace U1103
if defect.
Audio
at pin 8 of
U1103
?
Audio
heard
?
Check
voltages on
U1103.
OK?
Bad SINAD
Bad 20dB Quieting
No Recovered Audio
START
Check Controller (in the case of no audio).
Or else go to “B”
Yes
No
Spray or inject 10.7MHz
into XTAL Filter FL1102.
B
Yes
No
Check 2nd LO
(10.245MHz) at C1129.
LO
present
B
Yes
Biasing
OK
No
No
A
Yes
Check Q1106 bias
for faults.
Replace Q1106.
Go to B
Yes
No
Check circuitry around Y1101.
Replace Y1101 if defect.