Operating instructions

800/900 Band Troubleshooting Charts 9-3
START
No Power
Is B+ bias for
antenna switch
p
resent?
Check Q900 & Q901
Check GaAs Switches
Check Harmonic Filter
Is current
drain OK?
Is power OK?
Yes
No
No
Yes
Yes
No
No
Yes
Inspect/Repair TX
output network
Is control
voltage High
or Low?
Check
Power
Control
Is Pre-Driver
Current 60mA?
Low
High
Is TX_BUFF
input OK?
No
DONE
Check
VCO
Is Driver biased
correctly?
No
Yes
Inspect Final PA
Network
Check
TX_VCTRL
Check
Q702
Troubleshooting Flow Chart for Transmitter