Section Ток Trouble Shooting Ае Ара И А Ра Лп - Icom IC-720A Instruction Manual

SECTION. 10 TROUBLE SHOOTING
1. Power does not come on when | Power cable is improperly connected.
the switch is pushed.
Carefully reconnect power cable.
Power cord is connected with the polarity
reversed.
Disconnect the power cord, replace the blown fuse,
then reconnect the power cord observing proper
polarity.
Blown fuse. Check for the cause, then replace the fuse with a
spare one.
If using an IC-PS15, also check its fuse.
ІС-Р515 MAIN switch is in the OFF position. | Place MAIN switch in ON position.
2. No sound comes Тот the knob
speaker.
AF GAIN control
counterclockwise.
is completely | Turn the knob clockwise to a suitable level.
The unit is in the transmit mode, either by
the T/R switch or the PTT switch on the
microphone.
Put the unit in the receive mode.
The external speaker cable is connected to
the unit but not to the external speaker jack
on the external speaker.
Connect the cable to the speaker jack on the
external speaker.
The internal speaker cable is not connected. Connect the speaker connection.
Headphones are connected to the PHONES
jack.
Unplug the headphones.
RF GAIN control knob is turned fully
counterclockwise.
3. Sensitivity is low and only strong
signals are audible.
Turn the RF Gain control knob fully clockwise.
The antenna feed line is cut or shorted.
Check the feed line and correct any improper
condition.
The Attenuator is ON. Turn the Attenuator OFF.
During receive, the "5" meter is | RF GAIN control knob is turned fully
higher than the "0" position | counterclockwise.
even when there is no signal.
Turn the knob fully clockwise.
Only incomprehensible voices
are heard during SSB reception.
Receiving the wrong sideband. Set the sideband opposite the one you are receiving,
either USB or LSB.
The tone of the received signal | Maladjustment of the P.B. Tune control.
is very high or low pitched.
Set the P.B. Tune control knob to the clear tone
position, or P.B.T. OFF position.
7. No output power or low output | MIC GAIN setting is too low. Turn the MIC GAIN control clockwise to the
power. center (12 o'clock) position.
When SSB is desired, but the MODE is in | Set the MODE to the SSB (USB or LSB).
the CW or CW-N.
PTT switch is not functioning due to | Check the connection of the MIC connector and
improper connection of the mic connector. correct any problems.
The antenna feed line is cut or shorted. Check the antenna feed line and correct any
improper connection.
8. Тһе receive mode functions
properly and your signals are
transmitted, but you are unable
to make contact with another
Station.
The SIMP/DUP switch is in the DUP posi-
tion.
Set the SIMP/DUP switch to the SIMP position.
The receive frequency is offset from the
transmit frequency by the RIT control.
Turn OFF the RIT, or set the RIT control knob to
the center (12 o'clock) position.
The right side of the unit case
becomes a little hot.
As the right side of the case is used as a heat
sink for the transmitter driver transistors,
even during normal operation, it may get as
hot as 35°C (95°F) above room tem-
perature.
Make sure that the area around the unit has as
much ventilation as possible.
10.
The heat sink on the rear panel
becomes hot.
The heat sink on the rear panel is for the
final transistors and may become as hot as
40°C (104°F) above room temperature.
Make sure the area around the unit has as much
ventilation as possible.
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