As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING GROUND RUN AFTER ANNUAL INSPECTION, ENGINE OIL PRESSURE GAUGE WENT FROM A NORMAL INDICATION TO ZERO. TROUBLESHOOTING THE PROBLEM, FOUND ENGINE OIL PRESSURE INDICATOR FAILED. REMOVED FAULTY INDICATOR AND INSTALLED NEW INDICATOR. FUNCTIONAL CHECK OK.