D Transceiver Power; D Transmit And Receive; Troubleshooting - Icom IC-7851 Instruction Manual

16
MAINTENANCE

■ Troubleshooting

D Transceiver power

PROBLEM
Power does not come on
when the [POWER] key is
pushed.

D Transmit and receive

PROBLEM
No sound is heard from
the speaker.
Sensitivity is too low, and
only strong signals are au-
dible.
Received audio is unclear
or distorted.
The [ANT]() key does not
function.
Transmitting is impossible.
Output power is too low.
No contact possible with
another station.
Transmit signal is unclear
or distorted.
Repeater cannot be ac-
cessed.
POSSIBLE CAUSE
• Power cable is improperly connected.
• The internal power supply is turned OFF.
• Circuit breaker is tripped.
POSSIBLE CAUSE
• Volume level is too low.
• The squelch is closed.
• The transceiver is transmitting.
• The antenna is not properly connected.
• An antenna for another band is selected.
• The antenna is not properly tuned.
• The attenuator is activated.
• The operating mode is selected.
• The PBT function is activated.
• The Noise blanker is turned ON when receiv-
ing a strong signal.
• A preamp is activated.
• The noise reduction is activated and the [NR]
control is set too far clockwise.
• The antenna key has not been activated.
• The operating frequency is not inside a ham
band.
• [RF PWR] is set too far counterclockwise
• [DRIVE] is set too far counterclockwise
• [MIC] is set too far counterclockwise
• An antenna for another band is selected.
• The antenna is not properly tuned.
• RIT or ∂TX function is activated.
• The Split frequency function and/or Dualwatch
are activated.
• [MIC] is set too far clockwise
• The Split frequency function is not activated.
• The selected subaudible tone frequency is in-
correct.
The following chart is designed to help you correct
problems which are not equipment malfunctions.
If you are unable 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
• Re-connect the AC power cable correctly.
• Turn the internal power supply ON.
• Check for the cause, then re-set the circuit
breaker.
SOLUTION
• Rotate [AF] clockwise to obtain a suitable lis-
tening level.
• Turn [SQL] to 10 o'clock position to open the
squelch.
• Push [TRANSMIT] to receive or check the
SEND line of an external unit, if connected.
• Reconnect to the antenna connector.
• Select an antenna suitable for the operating fre-
quency.
• Hold down [TUNER] for 1 second to manually
tune the antenna.
• Push [ATT] several times to select "ATT OFF."
• Select a suitable operating mode.
• Hold down [PBT CLR] for 1 second to reset the
function.
• Push [NB] to turn the noise blanker OFF.
• Push [P.AMP] once or twice to turn the func-
tion OFF.
• Set the [NR] control for maximum readability.
• Set the antenna selection mode.
• Set the frequency to a ham band.
• Rotate [RF PWR] clockwise.
• Set [DRIVE] to a suitable position.
• Set [MIC] to a suitable position.
• Select an antenna suitable for the operating fre-
quency.
• Hold down [TUNER] for 1 second 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] to a suitable position.
• Push [SPLIT] to turn the function ON
• Reset the frequency in the Set mode.
16-10
REF.
p. 3-4
p. 3-4
p. 1-12
REF.
p. 4-4
p. 4-4
p. 4-13
—
p. 13-2
p. 13-7
p. 7-2
p. 4-10
p. 7-5
p. 7-11
p. 7-2
p. 7-12
p. 13-5
p. 4-6
p. 4-4
p. 4-14
p. 4-13
p. 13-2
p. 13-7
pp. 7-3,
8-5
pp. 7-10,
8-7
p. 4-13
p. 8-7
p. 5-38