As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PDX-EN ROUTE FROM PDX TO SEA, LANDING GEAR FAILED TO RETRACT AFTER TAKEOFF. RETURNED TO PDX. FOUND LANDING GEAR HYDRAULIC BYPASS HANDLE NOT FULLY STOWED. STOWED HANDLE AND RETRACTED AND EXTENDED LANDING GEAR FIVE TIMES. NO DEFECTS NOTED. NO PARTS REPLACED. AIRCRAFT RETURNED TO SERVICE.