As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
VERTICAL SPEED FUNCTION OF MCP INOP WHEN A AUTOPILOT IS ENGAGED. ALL OTHER MCP FUNCTIONS OPERATE NORMALLY WITH A AUTOPILOT ENGAGED. ALL FUNCTIONS OPERATE NORMALLY WITH B AUTOPILOT ENGAGED. GROUNDED - YES. PERFORMED DFCS MODE CONTROL PANEL TEST. FOUND NO CURRENT FAULTS. ETOPS GROUND VERIFICATION SUCCESSFUL, REF B737-800 FIM 22-11 TASK 803.