As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SEA - FLIGHT 2299 - ABORTED TAKEOFF AT 60 KNOTS FOR THE AUTOFEATHER WOULD NOT ARM. RETURNED TO THE GATE. MAINTENANCE FOUND FAULT CODE 64. PERFORMED FIM 61-20-02-810-834. OPERATIONAL CHECKS GOOD. AIRCRAFT RETURNED TO SERVICE. NO PARTS REPLACED.