As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT NR 6325 - NRT - DURING FLIGHT, SMOKE WAS OBSERVED IN THE COCKPIT. COCKPIT DOME LIGHT CIRCUIT BREAKER POPPED OUT AND THE SMOKE QUICKLY DISSIPATED. THE DOME LIGHTS WERE DEACTIVATED AND PROBLEM TRACED TO BALLAST. REMOVED AND REPLACED BALLAST ALL LIGHTS CHECK GOOD. (W)