Maintenance; Troubleshooting - Icom ic-718 Instruction Manual

10

MAINTENANCE

 Troubleshooting
The following chart is designed to help you correct
problems which are not equipment malfunctions.
PROBLEM
Power does not come on
when the [POWER] switch
is pushed.
No sounds come from the
speaker.
Sensitivity is low.
Receive audio is distorted.
Transmitting is impossible.
Output power is too low.
No contact possible with
another station.
Transmitted signals are
distorted.
Programmed scan does
not stop.
Programmed scan does
not start.
Memory scan does not
start.
The displayed frequency
does not change when
rotating the main dial.
52
POSSIBLE CAUSE
• DC power cable is improperly connected.
• Fuse is blown.
• Power supply is not turned ON.
• Volume level is too low.
• The squelch is closed.
• The transceiver is in the transmitting mode.
• The antenna is not connected properly.
• The antenna for another band is connected.
• The antenna is not properly tuned.
• The attenuator is activated.
• The operating mode is not selected correctly.
• The IF SHIFT function is activated.
• The Noise blanker function is activated.
• The preamp is activated.
• If installed, the Noise Reduction function is
activated and the [NR] control is set too high.
• The operating frequency is outside the select-
ed ham band.
• [RF POWER] is set too low.
• [MIC GAIN] is set too low.
• The selected antenna is for a different band.
• The antenna is not properly tuned.
• The RIT function is activated.
• The Split frequency function is activated.
• [MIC GAIN] too high.
• [COMP] function is activated.
• Squelch is open.
• [RF/SQL] is assigned to RF gain control and
squelch is open.
• The same frequencies have been entered in
scan edge memory channels P1 and P2.
• 2 or more memory channels have not been
entered.
• The dial lock function is activated.
• A Quick Set mode screen is selected.
• The internal CPU has mulfunctioned.
If you are not able to locate the cause of a problem
or solve it through the use of this chart, contact your
nearest Icom Dealer or Service Center.
SOLUTION
• Reconnect the DC power cable correctly.
• Check for the cause, fix it and then replace the
fuse with a spare one. (Fuses are in the DC
power cable and the internal PA unit.)
• Turn ON the power supply.
• Rotate [AF] clockwise to obtain a sutable lis-
tening level.
• Rotate [RF/SQL] to around the 10 o'clock po-
sition to open, and then properly the squelch.
• Turn off the transmit mode.
• Reconnect to the antenna connector.
• Connect an antenna suitable for the operating
frequency.
• Hold down [TUNER] for 2 seconds to manually
tune the antenna.
• Push [ATT] to set "ATT" or to OFF.
• Select the correct operating mode.
• Rotate SHIFT to the center position.
• Push [NB] to turn OFF the function.
• Push [P.AMP] to turn OFF the function.
• Set the [NR] control for maximum readability.
• Set the frequency within the selected ham band.
• Set [RF POWER] to a suitable level.
• Set [MIC GAIN] to a suitable level.
• Select an antenna suitable for the operating
frequency.
• Hold down [TUNE] for 2 seconds to manually
tune the antenna.
• Push [RIT] to turn OFF the function.
• Push [SPLIT] to turn OFF the function.
• Set [MIC GAIN] to a suitable level.
• Turn OFF [COMP].
• Set [RF/SQL] to the threshold point.
• Reset [RF/SQL] control assigned and set it to
the threshold point.
• Enter different frequencies in Scan Edge memory
channels P1 and P2.
• Enter 2 or more memory channels.
• Push [LOCK] to deactivate the function.
• Push [SET] to exit the Quick Set mode.
• Reset the CPU.
REF.
p. 12
p. 53
p. 2
p. 2
p. 6
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p. 3
p. 3
p. 20
p. 21
p. 21
p. 22
p. 23
p. 17
p. 42
p. 42
p. 10
p. 3
p. 21
pp. 7,
31, 32
p. 2
p. 28
p. 3
p. 26
p. 40
p. 40
p. 6
p. 41
p. 53