As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED. EMERGENCY DECLARED. DURING CLIMB THE LNAV/VNAV BECAME UNRESPONSIVE. AUTOPILOT DROPPED IN CWS MODE. RETURNED TO CLT. ACCOMPLISHED BITE CHECK OF VOR 1 RECEIVER IAW FIM 22-11-00. REMOVED AND REPLACED VOR 1 RECEIVER IAW AMM 34-51-01. SYSTEM CHECKS NORMAL.