As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: FLIGHT RETURNED TO JFK ON ACCOUNT OF BOTH FLIGHT DIRECTORS FAILED AFTER TAKEOFF. EMERGENCY DECLARED. MAINTENANCE ACCOMPLISHED FIM 22-11-00-810-80, FOUND NO FAULTS FOR F/D SYS ON SYS A OR B. REPLACED B SYS FCC IAW AMM 22-11-33. ACCOMPLISHED ALL REQUIRED CHECKS. ALL CHECKS NORMAL.