Troubleshooting Flow Chart For 25W Transmitter (Sheet 3 Of 3) - Motorola 6864115B62-C Detailed Service Manual

Troubleshooting Flow Chart for 25W Transmitter (Sheet 1 of 3)
Troubleshooting Flow Chart for 25W Transmitter (Sheet 3 of 3
2.2
Check Components
between ASFIC and
Q3441 before
replacing Q3441
ASFIC
YES
U0221 Pin 6
1-4V DC?
NO
Check Bias Tuning
before replacing ASFIC
U0221
Check Final PA Stage
Supply
Voltage
Bias 2 DC
0V
Voltage at
TP3406?
1-4V
NO
RF Voltage
at TP3401
>100mV?
YES
NO
RF Voltage
U3401 Pin 6
>3V?
YES
NO
RF Voltage
Q3421 Gate
>1V?
YES
RF Voltage NO
Q3441 Gate
>4V?
YES
Check Components
between Q3441 &
Antenna Connector
)
Replace Q3441
Check FGU (U3301)
Check Components
between TP3401 &
C3417
Check Components
between C3417 &
Q3421
Check Components
between Q3421 &
Q3441
3-5