As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
GPS NR 1 LOST SIGNAL ON RNAV GPS APPROACH. WARNING CAME UP ON G1000 DISPLAY. FOUND THAT ANTENNA BNC CONNECTORS WERE NOT CRIMPED ONTO EXTENDER CABLES INSTALLED BY MFG AND ALSO FOUND THAT THE ANTENNA WAS NOT PROPERLY SEALED AROUND PERIMETER OR ON FASTENER(S) BY MFG AT ORIGINAL OEM INSTALLATION. THUS THIS ALLOWED FOR WATER INTRUSION CAUSING CORROSION AND ANTENNA TO FAIL. REPLACED NR 1 ANTENNA AS REQUIRED. PERFORMED SYS OPS CHECKS, SYS OPS CHECKS SATISFACTORY.