As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AUTOPILOT DISC LIGHT ON & EICAS MESSAGE 'AUTOPILOT DISC' DISPLAYED WITH 2 AUTOPILOT SYSTEM ENGAGED IN COMMAND. AT CRUISE 380 M.80 CTR A-P DISCONNECTED. TRIMMED AND TRIED AGAIN, NO GO, LEFT AND RIGHT AUTOPILOT SYS OK. FOUND FAULT FCC-C. REPLACED CENTER FCC PER MM AND ACCOMPLISHED CATIII CHECK PER MM, OPS NORMAL.