As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) DURING MAINT WHEEL REPLACEMENT ON RAMP , FLIGHT CREW (ONLY PERSONNEL ONBOARD) NOTICED SMOKE IN THE COCKPIT (NO FIRE) . MAINTENANCE INSPECTION FOUND OVERHEAD READING LIGHT RHEOSTAT WAS SOURCE OF SMOKE. COCKPIT OVERHEAD PANEL ASSEMBLY WITH RHEOSTAT REPLACED. AIRCRAFT RETURNED TO SERVICE.