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MAINTENANCE AND INSPECTION
5.2 Troubleshooting
Typical causes
• Power supply fuse is blown.
• Malfunction in the POWER switch.
• Malfunction in the Display circuit.
• Malfunction in the control circuit.
• Malfunction in the handset.
• Malfunction in the transmitter or transmitter AF
circuit.
• Malfunction in the antenna.
• Break or short-circuit of antenna cable.
• Faulty contact in antenna connectors.
• Malfunction in the speaker.
• Malfunction in the SQL control.
• Malfunction in the panel or control AF circuit.
• Malfunction in the AF control circuit.
• Malfunction in the IF receiver circuit.
• Break in antenna or cables.
• Malfunction in receiver RF circuit.
• Malfunction in receiver PLL circuit or frequency
error.
• Malfunction in SQL control.
• Malfunction in control SQL circuit.
• Malfunction in transmitter or antenna duplexer
unit.
• Malfunction in transmitter control circuit of the
control unit.
• Malfunction in panel and handset PTT circuit.
• Malfunction in hook ON/OFF circuit of the panel.
• Malfunction in the microphone circuit of the
handset.
• Malfunction in panel unit and control AF circuit.
• Malfunction in transmitter and control AF circuit.
5.2.2
Guide to Locating Faults
Use the following table as a guide to locating the causes of malfunctions in the main unit.
No. Symptom
1 The channel number is not displayed.
2 TX is displayed but no sound is trans-
mitted.
3 No response to transmission or re-
ception sensitivity is poor.
4 No sound from the speaker (when
SQL
is turned fully counterclockwise).
5 Little sound from the speaker.
6 Noise is output from the speaker, but
the other station can not be received.
7 Turning
SQL
does not suppress
noise.
8 Transmission not possible. TX is not
displayed.
9 Transmission is sent, but modulation
impossible (TX is displayed).
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