As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
MAGNETO REMOVED FROM ENGINE FOR 500 HOUR INSPECTION IAW MM. REMOVED THE REAR COVER AND THE DISTRIBUTOR BLOCK FROM MAGNETO AND FOUND THE CARBON BRUSH WORN. CARBON DUST WAS FOUND ON THE FLAT PART OF THE CAP. WHERE IT LOOKS LIKE A SMALL SPARK LINE TO GROUND. THE WEAR ON THIS BRUSH IS ABOVE NORMAL FOR 500 HOURS. (PN M3004 BRUSH)