As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER TAKEOFF, GEAR WOULD NOT RETRACT. NOSE GEAR RED LIGHT WENT OUT, BOTH LT AND RT MAIN GEAR GREEN AND RED LIGHTS REMAINED ON WITH THE FLASHING GEAR HANDLE. ALL INDICATIONS NORMAL DURING GEAR EXTENSION. TROUBLESHOT SYS AND COULD NOT DUPLICATE. SERVICED NLG STRUT WITH NITROGEN IAW MM 32-212. CHANGED BOTH MLG DOOR PROX SWITCHES IAW MM 32-311. CHANGED NLG LT SQUAT SWITCH. F/T OK.