As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCREW NOTICED EMERGENCY LIGHTS FLICKERING IN FLIGHT. ACFT RETURNED TO FIELD. GROUND MX FOUND LT TRU COOLING FAN INOPERATIVE. LT TRU WAS R & R. OPS CHECK PERFORMED SATISFACTORY AND ACFT WAS RELEASED FOR TEST FLIGHT PURPOSES ONLY. FLIGHT TEST CHECKED SATISFACTORY. ACFT RELEASED TO FLIGHT STATUS.