As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER TAKE-OFF LANDING GEAR WOULD NOT RETRACT. CREW DECLARED AN EMERGENCY AND RETURNED TO CHS. MAINTENANCE TROUBLESHOT TO DEFECTIVE HYDRAULIC PRESSURE REGULATING VALVE. PRESSURE REGULATING VALVE WAS REPLACED WITH AN OVERHAULED UNIT. PERFORMED MULTIPLE EXTENSION/RETRACTION CYCLE TESTS. OPS CHECKS GOOD.