Motorola Radius CM300

Troubleshooting Flow Chart for 45 W Transmitter (Sheet 1 of 3) 3-5
2.1 Troubleshooting Flow Chart for 45 W Transmitter (Sheet 2 of 3)
Yes
Check bias tuning
before replacing
U504
Check PA
Stages
No or too low power when keyed
DC
Voltage
at Q101
base=0?
DC
Voltage
at U103
Pin 8
Check U510
Check resistive network at
Pin 9 and 10 of U103
before replacing U101
DC
Voltage at
C1095
Check Final PA Stages
ASFIC
U504
Pin 5 2-3V
Check components
between ASFIC and
Q105 before replacing
Q105
DC
Voltage at
U103 Pin
10=8.9V
Check Q101, R122,
R197, R153, R136,
R165, R168,
Check U103 before re-
placing U101
No
No
Yes
>5V
2 to 5V
2–3V
Yes
No
0V
<2V