As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
UPON SELECTION OF LANDING GEAR HANDLE DOWN, "GEAR DISAGREE LRN" WAS DISPLAYED AND NONE OF THE LANDING GEAR EXTENDED. THE QRH WAS REFERENCED AND AFTER THE THIRD CYCLE OF THE LANDING GEAR HANDLE (WHILE PROCEEDING WITH QRH 10D "LANDING GEAR WILL NOT EXTEND" CHECKLIST) THE GEAR FINALLY EXTENDED NORMALLY. NO IRREGULARITIES NOTED WITH THE HYDRAULIC SYSTEM.