As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING USE OF NAV LIGHTS, NAVIGATION LIGHT CIRCUIT BREAKER SWITCH WAS PLACED IN ON POSITION AND NAVIGATION LIGHTS DID NOT COME ON. PROBABLE CAUSE TO FAILURE WAS DUE TO INTERNAL FAILURE OF CIRCUIT BREAKER SWITCH. SEPARATE THE SWITCH FOR AN INDEPENDENT TOGGLE SWITCH WITH A SEPARATE CIRCUIT BREAKER FOR PROTECTION OR A BETTER DESIGN ON THE INTERNAL CIRCUITING OF THE CIRCUIT BREAKER SWITCH.