As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FOUND UPPER ANTI COLLISION LIGHT INOP. PARTS UPDATED NEED SNORKEL TO ACCESS LIGHT ASSY FROM TOP TO CHANGE. NO ACCESS FROM CABIN. REMOVED AND REPLACED ANTI COLLISION LIGHT DRIVER MODULE ASSEMBLY REF AMM TASK 33-44-01-960-807. UPPER LIGHT TURNS ON FOR ONE FLASH WHEN TURNED ON BUT WILL NOT CONTINUE FLASHING REQUIRES FURTHER TROUBLESHOOTING.