Icom IC-R75 - 11 Maintenance; Troubleshooting; Resetting the CPU

■ Resetting the CPU
Resetting CLEARS all programmed contents in
memory channels and returns programmed values
in set mode to their defaults.
When first applying power or when the function
seems to be displaying erroneous information, reset
the CPU as follows:
q Make sure receiver power is OFF.
w While pushing [UP Y] and [Z DN], push [POWER]
to turn power ON.
• The internal CPU is reset.
• The receiver displays its initial VFO frequencies when
resetting is complete.
11
36
MAINTENANCE
■ Troubleshooting
The following chart is designed to help you correct
problems which are equipment malfunctions.
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.
[POWER] [ZDN] [UPY]
PROBLEM POSSIBLE CAUSE SOLUTION REF.
POWER
Power does not come on
when the [POWER] switch
is pushed.
• DC power cable is improperly connected.
• Fuse is blown.
• 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 MAIN unit.)
—
p. 37
RECEIVE
No sound comes from the
speaker.
• Volume level is too low.
• The squelch is closed.
• Rotate [AF] clockwise to obtain a suitable
listening level.
• Rotate [RF/SQL] to 12 o’clock position to open
the squelch.
p. 2
p. 14
Sensitivity is low. • The antenna is not connected properly.
• The antenna for another band is selected.
• The attenuator is activated.
• Reconnect to the antenna connector.
• Select an antenna suitable for the operating
frequency.
• Push [ATT] to turn the function OFF.
—
p. 16
p. 16
Receive audio is distorted. • The operating mode is not selected correctly.
• PBT function is activated.
• Noise blanker function is activated.
• Preamp is activated.
• The optional noise reduction is activated and
the [NR] level is set too high.
• Select a suitable operating mode.
• Set [TWIN PBT] to the center position.
• Push [NB] to turn the function OFF.
• Push [P.AMP] once or twice to turn the function
OFF.
• Push [NR] to turn the function OFF.
p. 14
p. 15
p. 15
p. 16
p. 20
SCAN
Programmed scan does
not stop.
• Squelch is open.
• [RF/SQL] is assigned to RF gain control and
squelch is open.
• Set [RF/SQL] to the threshold point.
• Reset [RF/SQL] control assignment and set it to
the threshold point.
p. 14
pgs.
14, 30
Programmed scan does
not start.
• The same frequencies have been programmed
in scan edge memory channels P1 and P2.
• Program different frequencies in scan edge
memory channels P1 and P2.
p. 22
Memory scan does not
start.
• 2 or more memory channels have not been
programmed.
• Program 2 or more memory channels.
p. 22
Select memory scan does
not start.
• 2 or more memory channels have not been
designated as select channels.
• Designate 2 or more memory channels as select
channels for the scan.
p. 26
DISPLAY
“F.AGC” flashes in the
function display.
• A scan or band scope function is activated via
an optional RS-R75 remote control software.
• If these functions are not in use, push [AGC] to
deactivate the function.
—
The displayed frequency
does not change properly.
• The dial lock function is activated.
• The internal CPU has malfunctioned.
• Push [LOCK] to deactivate the function.
• Reset the CPU.
p. 13
See
below.