3-4 TROUBLESHOOTING CHARTS
2.0 Troubleshooting Flow Chart for 40W Transmitter (Sheet 1 of 3)
START
Yes
No
Check components between
Q100 and RF output,
Antenna Switch D104,
D103, VR102 and Q106
No or too low power when keyed
Current
increase when
keyed?
Check power settings, tuning
& components between U103
Pin 3 and ASFIC Pin 6 before
replacing ASFIC
Control
Voltage at
TP150
>4Vdc?
Check PA
Stages
>4A
Voltage
U103 pin 5 =
4.63V?
U103 Pin 3
<1.35Vdc
U100 Pin 3
>0.75Vdc
Check 9.3V
Regulator
U501
Yes
Yes
No
No
Yes
Check
U103
Check forward
Power Sense
Circuit
No
Short U100
Pin 3 to
ground
Voltage at
TP150 rises?
Check PA
Stages
Check Forward
Power Sense
Circuit
Yes
No
>500mA & <4A
<500mA
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