As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AC DIST CB 3C4 TRIPPED IN FLIGHT, MULTIPLE MALFUNCTIONS. AFTER TURNING OFF AC POWER, CLEANED AND INSPECTED INSIDE OF P6 PANEL AREA PER AMM 20-60-02-04. AFTER TURNING ON AC POWER, CYCLED AC DISTRIBUTION CB ON P6 3C4. NO CB'S POP-UP. AC GENERATION OPS TEST C/OUT WITH ALL ENGINES RUNNING PER AMM 24-20-00 AND 71-00-00. NO DEFECTS NOTED. REMOVED AND REPLACED BCU NR 1 PER AMM 24-23-01 AS A PRECAUTION AND CMC GROUND TEST PASSED IAW AMM 24-23-01/501.