As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
N1 PUSHBUTTON SWITCH ON THE MODE CONTROL PANEL WAS INOPERATIVE. ACFT GROUNDED. REMOVED, REPLACED AND TESTED DFCS MODE CONTROL PANEL IAW AMM 22-11-34. MCP INSTALLATION TEST PASSED. PERFORMED LRU REPLACEMENT TEST FOR MCP IAW AMM 22-11-34/501 AND LAND VERIFY TEST IAW AMM 22-11-00/201, ALL TESTS PASSED.