Garmin GNC 420 Maintenance Manual page 35

COM remote transfer key stuck
Heading input failure
CDI key stuck
OBS key stuck
COM is not responding
GPS has failed
GPS needs service
G/S is not responding
VLOC has failed
VLOC needs service
400 SERIES MAINTENANCE MANUAL
P/N 190-00140-05
Table 3-5. Static Messages (continued)
Verify that Remote Transfer Key Line is not stuck
before replacing COM Board
Replace Com Board (see paragraph 4.5.4)
Replace Main Board (see paragraph 4.5.5)
Replace Flex Cable (see paragraph 4.5.2.1)
Replace Key Board (see paragraph 4.5.2)
Replace Main Board (see paragraph 4.5.5)
Replace NAV Receiver (see paragraph 4.5.6)
Replace Com Board (see paragraph 4.5.4)
Replace GPS Module (see paragraph 4.5.5)
Replace GPS Module (see paragraph 4.5.5)
Replace G/S Receiver (see paragraph 4.5.6)
Replace NAV Receiver (see paragraph 4.5.6)
Replace NAV Receiver (see paragraph 4.5.6)
Page 3-9
Rev. C