As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AT GATE IN CLT, SMOKE (PERCEIVED AS ELECTRICAL) WAS COMING FROM MODE CONTROL PANEL. HAD TO SHUT OFF ALL ELECTRICAL TO GET IT TO STOP. MAINTENANCE REMOVED AND REPLACED THE FLIGHT CONTROL UNIT IAW AIRBUS MAINTENANCE MANUAL 22-81-12-0401.