As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING AIRCRAFT TEST FLIGHT THE LANDING GEAR HANDLE WOULD NOT RETRACT. THE FIRST OFFICER PRESSED THE DOWNLOCK RELEASE AND THE GEAR OPERATED NORMALLY. MAINTENANCE IN ABI PERFORMED LANDING GEAR EXTENSION AND RETRACTION CHECKS, COULD NOT DUPLICATE PROBLEM.