As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ALTITUDE SELECTOR, ON THE MODE CONTROL PANEL WAS INTERMITTENT. CAN NOT ALWAYS SELECT THE ASSIGNED ALTITUDE. ACFT GROUNDED. REPLACED DFCS MODE CONTROL PANEL, OPS CHECKED GOOD IAW MM 22-11-34, ACCOMPLISHED LLM MAINT TEST FOR MODE CCONTROL PANEL AND ALL TESTED GOOD IAW MM 22-11-34.