As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
IN CRUISE AT FL350 AUTOPILOT B RANDOMLY DISENGAGED. GROUNDED - YES. REMOVED AND REPLACED MCP PER B737-900 AMM 22-11-34. OPEN AND TAGGED 4 CIRCUIT BREAKERS. CLOSED AND REMOVED TAGS FROM 4 CIRCUIT BREAKERS. LAND VERIFY TEST PASSED PER 22-11-00. MCP INSTALLATION TEST PASSED PER AMM 22-11-34. DFCS LRU REPLACEMENT TEST PASSED PER 22-11-34.