What was found
#4 AC DISTRIBUTION CB TRIPPED AFTER TAKEOFF, 500'. MULTIPLE MALFUNCTIONS. FOUND SIGNS OF ELECTRICAL ARCING AT THE #4 AC DISTRIBUTION CB AND #4 TR/CB. REMOVED AND REPLACED #4 AC DISTRIBUTION C/B AND TR C/B REF AMM 24-22-02 AND SWPM 20-30-00. ALSO REMOVED AND REPLACED #4 TRU PER AMM 24-31-01. PERFORMED INSULATION AND CONTINUITY CHECK FROM AC DIST C/B TO ALL RELATED USERS PER WDM 24-51-42. NO DEFECT NOTED. INSPECTED IDG FEEDER CABLES. NO DEFECTS NOTED. #4 IDG OPS CK GOOD PER AMM 24-11-00. PERFORMED ALL 4 ENGINE RUN AND AC GEN TEST PER AMM 24-00-00, AC SYSTEM OPS NORMAL.