Fuse Replacement; Cpu Resetting - Icom IC-820H Instruction Manual

POSSIBLE CAUSE
@ Fuse is biown.
SOLUTION
* Check for the cause, then replace the fuse with | See
@ spare one. below
(Fuses are insialled in two places, in the DC
power cable and in the PA unit.)
[PROBLEM
Power does not come on
when [POWER] is
pusned IN.
p. 49
p. 12
check the fuse in the DC power cable.
9 Rotate [SQL] counterclockwise to open the
squelch.
No sound comes from
the speaker.
° The squelch is closed.
t @ Turn OFF the tone squelch to monitor all
signals.
® An optional tone squelch is in use.
* CW-narrow mode is selected when an op- | 9 Select another mode.
tional CW-narrow filter is not installed.
Sensitivity is low » The attenuator is turned ON. 9 Turn OFF the [ATT] switch.
RECEIVE
* The VHF antenna is connected to the UHF
antenna connector and vice versa.
e Check the antennas and antenna connections.
Preamplifier does not
function.
AG-35 (430 MHz) if needed.
Output power is low. e The VHF antenna is connected to the UHF | » Check the antennas and antenna connections.
antenna connector and vice versa.
- Make sure [PWR/COMP] functions as the | 25, 26
power selection in the set mode.
7 G Fuse replacement
TRANSMITTER
DISPLA
CPU backup battery
If the fuse blows or the transceiver stops functioning, The !C-820H has a lithium backup battery on the
find the source of the problem if possible, and replace back side of the front panel for retaining memory
the damaged fuse with a new, rated fuse.
information.
The usual life of the backup battery is
approximately 5 years.
@ DC power cable fuse
: CAUTION: If the lithium battery is incorrectly re-
placed, it could explode. Replace with a CR-2032
, or equivalent type.
GG
¢ Backup battery location MAIN unit side :®
® Internal fuse
Front panel side :©
An internal fuse is installed on the line affecting all
circuits except the V/UHF PA circuits. The fuse is
located in the PA-B unit. See the leit page for loca-
tion.
«Internal fuse: FGMB 125V/5A
CPU resetting
If the function display shows erroneous information
when first applying power, the CPU may require
resetting. CPU resetting clears all memory infor-
mation. When the backup battery. is exhausted, the transceiver
* CPU RESET PROCEDURE: transmits and receives normally but cannot retain memory
While pushing [MW], turn power ON. information.
50