What was found
(CAN) ELECTRICAL SYSTEM FAIL AND ELECTRICAL SYSTEM FAULT CAS POSTED ON THE GROUND WITH APU GEN ON-LINE. AC SYNOPTIC PAGE MISSES ALL FLOW LINES AND DC SYNOPTIC PAGE MISSES APU BATTERY INFO. FOLLOWING VISUAL INSPECTION OF SECONDARY SECTION OF THE ACPC, THERE WAS A NOTICEABLE ODOR OF BURNING AND CARD 10, 11 AND 12 SHOWED VISIBLE SIGNS OF ARCING. ALL CARDS OF THE LEFT ACPC WERE REMOVED AND INSPECT FOR FOREIGN DAMAGE. TWO AC SSPC CARDS (A23 AND A24 HAVE EVIDENCE OF BURN THROUGH. ALL OTHER CARDS WERE VISUALLY INSPECTED WITH NO OBVIOUS DAMAGE FOUND, THEY HAVE SIGNS OF CARBON BLACK ONLY.