Troubleshooting Flow Chart - HYT tc-320 Service Manual

Troubleshooting Flow Chart

Transmit Circuit
Low TX
power
voice channel
(Output ports of
MIC，U501,
MOD_OUT).
Check the
antenna.
No sound
transmission
Normal TX
power supply?
Check the
LED of D602
U601,
glows red？
Check the
TX channel.
Check Q401,
Q402, Q403
and U501.
Start
No LED fails to
glow/flash.
No
Check the TX
power supply.
Yes
No
TX VCO
locked?
Yes
Replace
D602.
43
TC-320 Service Manual
Replace
D602.
No
Check the
TX VCO.
Yes
Check the
APC circuit.