ⓐ
Battery could completely be discharged.
ⓑ
Battery cell wrong inserted?
ⓒ
Contact problem between Battery and Radio?
②
Fail to transmit
ⓐ
Run out of battery or charge problem.
ⓑ
Fault of PTT key
ⓒ
Fault of Q4, Q5.
③
Transmitter works but frequency is unmatched
ⓐ
defective frequency synthesizer.
ⓑ
defective X-tal (X2).
④
No audio modulation (Tx power and Tx frequency are normal)
ⓐ
Problem of microphone or mic connector.
ⓑ
IC U7 problem.
⑤
Tx is set when switch is on.
ⓐ
Tx switch problem
2) RECEIVER
①
Rx does not work
ⓐ
Speaker line open problem or connector problem.
ⓑ
Receiver power circuit problem.
ⓒ
Audio amplifier Base band IC U4 problem.
②
Only noise sound
ⓐ
U12 problem.
ⓑ
VCO problem.
③
Rx sensitivity is weak
ⓐ
Antenna mounting problem.
ⓑ
Front-End circuit problem.
ⓒ
Local oscillation frequency deviation.
