RP6500 User’s Manual
Page 27 of 31
Problems and troubleshooting
No. Problems
Solution
1
No display after
switched on.
A
．
Battery power may be insufficient. Recharge or replace the battery pack.
B
．
The power switch may be broken, replace the switch.
C
．
CPU may be broken, replace the IC.
D
．
Regulator tube Q45 may be broken
，
replace the IC.
2 Phase
locked
loop unlocked
（
with “tick,
tick”
）
A
．
Phase locked loop Crystal Oscillator X1 may be broken, replace it.
B
．
Oscillator tube may be broken, replace it.
C
．
Phase locked loop IC2 may be broken
，
replace the IC.
3 Cannot
transmit.
A
．
The frequencies of both users are not the same, select the same frequency
channel again.
B
．
The CTCSS/DCS signaling of both users are not the same, set it with PC.
C
．
Beyond the efficient communication range.
4 No
signal
A
．
Make sure the antenna is well connected.
B
．
Low sensibility, trimming “computer test mode”
。
C
．
HF amplifier may be broken, replace it.
D
．
The squelch level is too high, which makes the squelch unable to switch on,
reset it by PC.
E
．
Mixer tube
Q19 may be broken, replace the tube.
F
．
Frequency Modulation IC4 may be broken, replace the IC.
5 The
transmitting
red light is on, but
no voice is heard
A
．
Power-amplifier tube no power output, replace the tube.
B
．
Replace the microphone if it is broken.
C
．
Operational Amplifier IC14 may be broken, replace it.
6 Receiving
green
light is on, but no
voice is heard
A
．
Replace the speaker if it is broken.
B
．
Audio power amplifier IC9 may be broken, replace it.
C
．
Switch Tube
Q48 may be broken, replace it.
D
．
Operational Amplifier IC6 may be broken, replace it..
7 Abnormal
programming
A
．
Make sure the wires are well connected.
B
．
Abnormal output of the RS-232 serial port of the computer, check the computer .
C
．
Abnormal connection of MIC and SPK jack, check the jack.
