Motorola GM328

Troubleshooting Flow Chart for 25W Transmitter 3-5
2.2 Troubleshooting Flow Chart for 25W Transmitter (Sheet 3 of 3)
Check Final PA Stage
NO
0V
1-4V
Bias 2 DC
Voltage at
TP5406?
YES
RF Voltage
at TP5401
>100mV?
YES
RF Voltage
U5401 Pin 6
>3V?
Supply
Replace Q5441
Check FGU (U5301)
NO
Check Components
between
TP5401 &C5417
NO
YES
ASFIC
U0221 Pin 6
1-4V DC?
Check Bias Tuning
before replacing ASFIC
U0221
Check Components
between ASFIC and
Q5441 before
replacing Q5441
YES
RF Voltage
Q5421 Gate
>1V?
NO
Check Components
between
C5417 & Q5421
YES
RF Voltage
Q5441 Gate
>4V?
NO
Check Components
between
Q5421 & Q5441
Check Components
between Q5441 &
Antenna Connector
Voltage