Bout Protection Indications; Opening The Transceiver's Case; About Protection Indications - Icom IC-7851 Instruction Manual

16
MAINTENANCE

■ About protection indications

The transceiver has a 2 step protection function to pro-
tect the final power amplifiers.
The function detects the power amplifier temperature
and activates when the temperature becomes ex-
tremely high.
• Power down transmission
Reduces the transmit output power to 100 W.
"LMT" appears beside the transmit indicator
during transmit.
• Transmission inhibit
Disables the transmitter.
The transmit indicator is displayed in gray during
transmit.
When the function is activated, wait until the power
amplifier cools down using the transceiver in the stand-
by or receive mode.
NOTE: DO NOT turn the transceiver power OFF.
The internal cooling fan does not function, so it will
take longer to cool the transceiver.
The power amplifier temperature can be monitored in
the multi-function meter, TEMP gauge.

■ Opening the transceiver's case

Follow the case opening procedures shown here when
you want to replace the clock backup battery or inter-
nal fuse.
RWARNING! DISCONNECT the AC power cable
from the transceiver before performing any work on
the transceiver. Otherwise, there is danger of elec-
tric shock and/or equipment damage.
CAUTION: The transceiver weighs approximately
23.5 kg (52 lb). Always have two people available to
lift or invert over the transceiver.
q Remove the 8 screws from the top of the trans-
ceiver and the 6 screws from the sides, then lift up
the top cover.
w Turn the transceiver upside-down.
CAUTION: NEVER HOLD THE MAIN DIAL OR
ANY OTHER KNOBS when the transceiver is up-
side down. This may damage the transceiver.
e Remove 6 screws from the bottom, and the 6
screws from the sides, then lift up the bottom
cover.
16-8
Check the temperature