Service manual

August 30, 2002 99R85452E01-O
7-12
VHF Band Information
: Troubleshooting Charts
Figure 7-8.
Troubleshooting Flow Chart
for Transmitter
Start
No
Power
Is
+5VTX and TXB+
OK?
Is
current
OK?
Is
DAC TX High
or Low?
Is
Pin
OK?
Check
Q201, Q202, Q206
& Q209
Check
Voltages in
Power Control
Circuit
Check
Voltages in
PA Line-up
Troubleshoot
VCO
Done
Power
OK?
1. Check Pin Diodes
2. Check Harmonic Filter
Inspect/Repair
TX Output
Network
NO
NO
LOW
HIGH
YESNO
NO
YES
YES
YES
Check Pin to
Q419 Pin 1
Is