![background image](http://html.mh-extra.com/html/icom/ic-7850/ic-7850_instruction-manual_612352242.webp)
16-10
16
MAINTENANCE
■
Troubleshooting
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.
D
Transceiver power
D
Transmit and receive
PROBLEM
POSSIBLE CAUSE
SOLUTION
REF.
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.
• 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.
• 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.
—
PROBLEM
POSSIBLE CAUSE
SOLUTION
REF.
Power does not come on
when the [POWER] key is
pushed.
• Power cable is improperly connected.
• The internal power supply is turned OFF.
• Circuit breaker is tripped.
• Re-connect the AC power cable correctly.
• Turn the internal power supply ON.
• Check for the cause, then re-set the circuit
breaker.