As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
HEADING DISPLAY PANEL MODE CONTROL IS FLICKERING. GROUNDED - YES. INITIAL EVALUATION, CONFIRMED DEFECT. REMOVED AND REPLACED DFCS MCP IAW B737-900 AMM 22-11-34-000/400-801, FLICKERING STOPPED. PERFORMED DFCS LRU REPLACEMENT FOR MCP AND LAND VERIFY IAW AMM 22-11-00/201, ALL TESTS PASS.