Motorola CM140

3-6 TROUBLESHOOTING CHARTS
2.2 Troubleshooting Flow Chart for 25W Transmitter (Sheet 3 of 3)
No
Yes
Yes
No
Check Final PA Stage
PA_Bias
Voltage at
R134
2.1V
RF Voltage
after C1044 -
>100mV?
Voltage
across R122
>50mV?
RF Voltage
Q105 gate
>100mV?
RF Voltage
Q100 gate
>1.5V?
Check components
between Q100 &
antenna connector
Replace Q100
Check FGU
Check components
between C1044 &
C1117
Check components
between C1117 &
Q105
Check components
between Q105 &
Q100
No
No
Yes
Yes
2-3V
Supply Voltage
Check Bias Tuning
R134, R131, R106
before replacing
ASFIC U504
<2V