ACR Electronics ME406 Series Abbreviated Component Maintenance Manual page 47

COBHAM AVIONICS WULFSBERG ELECTRONICS
ABBREVIATED COMPONENT MAINTENANCE MANUAL
CODE PROBABLE CAUSE
Open or short condition on antenna
output or coax cable
4-Flash
Impedance presented by antenna
Transmitter module faulty
(frequency out of limits)
Indicates there is no navigation position data present (long message protocol only)
Aircraft navigation system off
Faulty system interface wiring or
5-Flash
No navigation interface installed
6-Flash
7-Flash Operating time is >1 hour
Electrical circuits faulty
ME406 (453-6603), ME406HM (453-6604)
Indicates 406 or 121.5 MHz output power is low
connections
Indicates G-Switch loop between pins 5 and 12 is not present
Jumper open
Jumper missing
Indicates a battery problem
POSSIBLE SOLUTION
Check coax cable and connections
Check antenna for proper installation
Lengthen or shorten antenna coax cable
length by 4 to 6 inches
Cannot be repaired in field - Return to
factory for servicing
Turn on navigation system
Check wiring and connections for
continuity and security
Install navigation interface
Reprogram to short message
Verify D-Sub connector jumper is installed
by checking for less than 1Ω between pins
5 and 12. Repair as necessary.
Install D-Sub jumper between pins 5 and
12 in D-Sub connector.
Replace battery pack
25-62-30
Page 47 of 88
APR 06/10