As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER TAKE OFF, UNRELIABLE POSITION ON FMS 1. MFD 1 DID NOT UPDATE. NON-ALERTED DECLARED EMERGENCY INBOUND TXK FOR NAVIGATION FAILURE. C/A: PERFORMED ADC SYSTEM OPERATIONS CHECK, IAW AMM 34-15-00. OPERATIONS CHECK GOOD. POSITION INDICATION SHOWN ON MFD 1 DURING ADC SYSTEM. OPERATIONS CHECK.