As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
APPROXIMATELY AN HOUR INTO FLT, THE PIC EXPERIENCED SMOKE IN THE COCKPIT. DECLARED AN EMERGENCY AND RETURNED TO MIA. THE LANDING WAS WITHOUT INCIDENT. AFTER INVESTIGATION, THE CAUSE FOR THE SMOKE WAS AN INTERNAL SHORT IN THE INSTRUMENT AMP RACK. THE INSTRUMENT AMP RACK WAS REPLACED AND THE A/C RETURNED TO SERVICE.