FP520 Service Manual
Page 29 of 64
Chapter 10 Troubleshooting
No.
Problems
Causes and Solutions
1
Power-on Failure
A
．
The battery pack may be out of power. Please charge it or
change to a new one, then try again.
B
．
The power switch failure. Change to a new power switch.
C
．
CPU failure. Change to a new CPU.
D
．
Protective tube F100 failure. Change to a new protective tube.
2
PLL is unlocked
（
beeping
）
A
．
The PLL crystal oscillator is broken, please change to a new one.
B
．
The oscillation tube is broken, please change to a new one.
C
．
The PLL chip IC300 is broken
，
please change to a new one.
3
Communication Failure
A
．
The frequency is not the same. Please reselect a channel with
the same frequency
B
．
The signaling codes of CTCSS/DCS are different
，
please reset
them with the computer.
C
．
Beyond the communication range.
4
No Signal
A
．
The antenna is in poor contact
，
please fasten it again.
B
．
Low sensitivity
，
adjust the parameter in
the “test mode”.
C
．
The high-mu tube Q703 is broken, please change it.
D
．
The squelch level is too high to turn it on, please adjust the
squelch level.
E
．
Mixer tube Q702 is broken, please change it.
F
．
FM processing chip IC700 is broken, pleas change to a new IC.
5
No
voice
on
the
receiving radio when the
indicator glows red on
the transmitting radio.
A
．
The power amplifying tube is broken with no power output,
please change it.
B
．
The microphone is broken, please change it.
C
．
The operational amplifier Q601 is broken, please change it.
6
No voice received when
the
indicator
glows
green.
A
．
The speaker is broken, please change it.
B
．
The audio power amplifier U800 is broken, please change to a
new IC.
C
．
The switch diode Q801is broken, please change it.
7
Abnormal Programming
A
．
Improper connection, please check the cable connection.
B
．
The computer serial port output is abnormal, please check the
computer.
C
．
The earphone jack is in poor contact, please check it and change
it if broken.
Summary of Contents for FP520
Page 1: ... 键入文档副标题 gh 选取日期 在此处键入文档的摘要 摘要通常是对文档内容的简短总结 在此处键入文档的摘要 摘要 通常是对文档内容的简短总结 ...
Page 44: ...FP520 Service Manual Page 43 of 64 Figure 1 FP520 01 Mainboard Schematic Diagram 136 174MHz ...
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Page 54: ...FP520 Service Manual Page 53 of 64 Figure 4 FP520 02 Mainboard Schematic Diagram 400 470MHz ...
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Page 64: ...FP520 Service Manual Page 63 of 64 Figure 7 KBC 51 7 4V Electrical Schematic Diagram ...
