As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PILOT WRITE UP AT END OF DAY. WHEN START BUTTON IS DEPRESSED (NR 2 ENGINE) STARTER CHATTERS AND HAS GRINDING NOISE. WHEN RELEASED AND DEPRESSED AGAIN, A FAIRLY NORMAL START IS ACHIEVED. UPON INSPECTION OF STARTER GENERATOR, BRUSHES FOUND TO BE DISINTEGRATED. ARMATURE ALSO DAMAGED DUE TO FAILED BRUSHES.