As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIR TURNBACK, EVERY FUNCTION ON MODE OF CONTROL PANEL UNABLE TO SET. ON ARRIVAL FOUND ALT AND IAS/MACH DISPLAYS MISSING DIGITS AND BACKLIGHTING NOT WORKING ON MSP. REMOVED AND REPLACED AUTOPILOT MODE SELECT PANEL W/REFERENCE MM 22-11-02. PERFORMED TEST IAW MM 22-10-00-5 AND MCDP GROUND TEST 04. CHECKS GOOD.