As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FAN RETURNED TO MFG FOR OVERHAUL, THE FAN WAS DISASSEMBLED AND FOUND TO HAVE AN ARMATURE OF NOT MFG DESIGN. INSTALLED THE ARMATURE LAMINATIONS ARE NOT COATED, ALLOWING THE ARMATURE TO RUST. THE WINDINGS HAVE EXCESSIVE COATING WHICH CAUSED THE ARMATURE TO RUB THE BRUSH HOLDER. THIS WAS COMPENSATED BY SOMEONE REPOSITIONING THE BRUSH HOLDER FURTHER AWAY FROM THE COMMUTATOR WHICH CAUSED AN IN ACCURATE BRUSH LOAD.