As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING A 500 HOUR INSPECTION OF MAGNETOS, IMPULSE COUPLING ON EACH MAG WAS FOUND TO HAVE CRACKS IN THE HUB BASE PLATE, LOCATED AT THE FULL ADVANCE STOP NOTCH. CRACKS RADIATE FROM THE SHARP-CORNERED FEATURE OF THE NOTCH OF THE PLATE. DEFECT DETECTED USING MAGNETIC PARTICLE NDT TESTING.