As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AT THE GATE WITH APU POWERING BUSES, THE APU ELECTRICAL DISCONNECTED FROM BOTH BUSES. AFTER 10 SECONDS THE APU BLUE LIGHT CAME BACK ON AND WE POWERED BOTH BUSES WITH THE APU. GROUNDED - YES. REMOVED & REPLACED APU INLET PRESSURE SENSOR REF AMM 49-52-31, REPLACED APU INLET TEMPERATURE SENSOR REF AMM 49-61-31. RAN APU 3 START/SHUTDOWN- NO REPEAT ON FAULT. OPS NORMAL.