As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT 6470 - EWR-RIC - DURING CRUISE, AN UNSCHEDULED LANDING DUE TO HEADING COMPARATOR LIGHT ILLUMINATED. AIRCRAFT RETURNED TO GATE WITH NO FURTHER PROBLEMS. MAINTENANCE REMOVED AND REPLACED LEFT AHRS, OPS CHECK OK. AIRCRAFT WAS RELEASED AND APPROVED FOR RETURN TO SERVICE. (M)