As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER T/O IN ATL - GEAR DISAGREE WARNING NOSE GEAR DID NOT RETRACT. RAN QRH, NOSE GEAR (AND MAINS) CAME DOWN AND LOCKED. AIRCRAFT RETURNED TO ATL AFTER T/O. EMERGENCY DECLARED. FLT 4785 DEL 137 MINS. REMOVED AND REPLACED NLG PRIORITY VALVE, LK AND OPS CHECKD GOOD. REMOVED AND REPLACED NLG SELECTOR VALVE, LEAK AND OPS CHECKED. REF CRJ MM 32-33-10. (B)