Maintenance; Troubleshooting - Icom IC-756PRO Instruction Manual

11

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 sound comes from the
speaker.
Sensitivity is low.
Receive audio is distorted.
The [ANT] switch does not
function.
Transmitting is impossi-
ble.
Output power is too low.
No contact possible with
another station.
Transmitted signals are
distorted.
Repeater cannot
accessed.
Programmed scan does
not stop.
Programmed scan does
not start.
Memory scan does not
start.
Select memory scan does
not start.
74
POSSIBLE CAUSE
• DC power cable is improperly connected.
• Fuse is blown.
• Volume level is too low.
• The squelch is closed.
• The transceiver is in the transmitting condition.
• The antenna is not connected properly.
• The antenna for another band is selected.
• The antenna is not properly tuned.
• The attenuator is activated.
• The operating mode is not selected correctly.
• PBT function is activated.
• Noise blanker function is activated.
• Preamp is activated.
• The noise reduction is activated and the [NR]
control is set too far clockwise.
• The antenna switch has not been activated.
• The operating frequency is not set to a ham
band.
• [RF POWER] is set too far counterclockwise.
• [MIC GAIN] is set too far counterclockwise.
• The antenna for another band is selected.
• The antenna is not properly tuned.
• RIT or ∂TX function is activated.
• Split frequency function and/or dualwatch are
activated.
• [MIC GAIN] is set too far clockwise.
be • Split frequency function is not activated.
• Programmed subaudible tone frequency is
wrong.
• Squelch is open.
• [RF/SQL] is assigned to RF gain control and
squelch is open.
• The same frequencies have been programmed
in scan edge memory channels P1 and P2.
• 2 or more memory channels have not been
programmed.
• 2 or more memory channels have not been
designated as select channels.
If you are unable to locate the cause of a problem or
solve it through the use of this chart, contact your near-
est Icom Dealer or Service Center.
SOLUTION
• Reconnect the DC power cable correctly.
• Check for the cause, then replace the fuse with
a spare one.
(Fuses are installed in the DC power cable and
the internal PA unit.)
• Rotate [AF] clockwise to obtain a suitable
listening level.
• Rotate [RF/SQL] to 10 o'clock position to open
the squelch.
• Push [TRANSMIT] to receive or check the
SEND line of an external unit, if desired.
• Reconnect to the antenna connector.
• Select an antenna suitable for the operating
frequency.
• Push [TUNER] for 2 sec. to manually tune the
antenna.
• Push [ATT] one or more times to select "ATT
OFF."
• Select a suitable operating mode.
• Push [PBT CLR] for 2 sec. to reset the function.
• Push [NB] to turn the function OFF.
• Push [P.AMP] once or twice to turn the function
OFF.
• Set the [NR] control for maximum readability.
• Set the antenna switch in set mode to "Auto" or
"Manual."
• Set the frequency to a ham band.
• Rotate [RF POWER] clockwise.
• Set [MIC GAIN] to a suitable position.
• Select an antenna suitable for the operating
frequency.
• Push [TUNER] for 2 sec. to manually tune the
antenna.
• Push [RIT] or [∂TX] to turn the function OFF.
• Push [SPLIT] and/or [DUALWATCH] to turn the
function OFF.
• Set [MIC GAIN] to a suitable position.
• Push [SPLIT] to turn the function ON.
• Reset the frequency using set mode.
• Set [RF/SQL] to the threshold point.
• Reset [RF/SQL] control assignment and set it to
the threshold point.
• Program different frequencies in scan edge
memory channels P1 and P2.
• Program 2 or more memory channels.
• Designate 2 or more memory channels as select
channels for the scan.
REF.
p. 17
p. 75
p. 2
p. 3
p. 2
—
pgs. 5,
45
p. 48
p. 5
p. 26
p. 26
p. 27
p. 5
p. 27
p. 45
p. 24
p. 3
p. 2
p. 5
p. 48
p. 6
pgs. 7
31, 32
p. 2
p. 7
p. 46
p. 3
pgs.
3, 68
p. 52
p. 52
pgs. 51,
59