As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
NDIS 651 53-20 0010740 05JUL19 SBY CLOSE WHILE TROUBLESHOOTING APU BATT 1 OFF BUS MESSAGE. TRANSCRIBED FROM LP 189608 FOUND DAMAGE ON STRUCTURE BEHIND UP SHORT LOCATED AT THE LOWER HALF OF FRAME 80. DAMAGE THAT WAS FOUND WAS ARCING. FACT 05JUL19 11:41 SBY REPAIRED DAMAGED AREA IAW EO1-53-19-0259. SEE LOG BOOK PAGE 189611 SEQ 1 FOR APU CORRECTIVE ACTION.