As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING WALK AROUND, FOUND APU OIL FILTER DPI POPPED AND DAMAGED. ACFT GROUNDED. VERIFIED MAG DRAIN PLUG HAS NO CONTAMINATION, IAW AMM 49-91-81. REMOVED APU FILTER AND VERIFIED NO CONTAMINATION. REMOVED AND REPLACED OIL FILTER DPI INDICATOR AND INSTALLED NEW OIL FILTER IAW AMM 49-91-12 AND 49-81-13. LEAK CHECKED GOOD AND DPI REMAINED SET.