Troubleshooting Flow Chart For 25W Transmitter (Sheet 3 Of 3) - Motorola CM140 Service Information

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