As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
MIA INFLIGHT T783 - DURING GEAR RETRACTION ALL THREE GEAR UNSAFE LIGHTS ILLUMINATED AND GREEN HYDRAULIC SYSTEM QUANTITY FLUCTUATED RAPIDLY. PRESSURE ALSO FLUCTUATED. RETURNED TO MIA AND LANDED WITHOUT INCIDENT. FOUND 406B SWITCH ON NOSE GEAR TELESCOPIC DRAG STRUT FAULTY. REPLACED 406B MICROSWITCH. SYSTEM GROUND CHECKED NORMAL OPERATION.