What was found
AIRCRAFT GROUNDED - COMMAND B AUTOPILOT DISENGAGED IN FLIGHT, CAUTION & WARNING SYSTEM: R & AP/P/RST (RIGHT AUTOPILOT, PUSH TO RESET) ILLUMINATED, COULD NOT RE-ENGAGE. FIRST OFFICER'S FLIGHT DIRECTOR ALSO FAILED. REPLACED LEFT AND RIGHT FMCS. ACCOMPLISHED SOFTWARE UPLOAD FOR BOTH, PER AMM 34-61-00, ALL CHECKS OKAY. ACCOMPLISHED LAND VERIFICATION PER AMM 22-11-00, ALL CHECKS PASSED, OKAY FOR SERVICE.