Garmin GTR 225 Pilot's Manual page 40

Problem
GTR 225 does not power on
GTR 225 does not transmit
Intercom doesn't function
Can't change active frequency
Display shows
"Com Radio Needs Service" at
start-up
4-2
Possible Cause
No power to the
GTR 225
Faulty electrical
wiring or connection
No power to Com
Mic key connection
It can be enabled
or disabled via a
remote mounted
switch or via the
menu.
No voice activation,
or if must talk too
loud
Com Radio not
communicating. The
radio may also be in
lockout mode. In this
case the radio would
be tuned to 121.50
and the active freq
would not be able to
be changed.
Corrupted system
calibration
parameters
Table 4-1 Troubleshooting
Garmin GTR 225/225A/225B Pilot's Guide
Action
Check power connections,
breakers, and main
avionics switch
Contact your dealer to
perform electrical system
test
Check power connections
Check Mic key input
connection
Check connections
Check ICS page, Intercom
On/Off, Adjust Intercom
If in Lock Out mode,
press the external Com
FLIP/FLOP key for two
seconds to return to
normal operation or cycle
the avionics power. If the
condition persists, contact
dealer.
Contact factory
190-01182-00 Rev. A