As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CLIMB OUT AT FL 200 VISIBLE SMOKE & A BURNING SMELL WERE PRESENT IN THE CABIN & COCKPIT. FOLLOWED EPC & AOM1 PROCEDURES CONDUCTED EMER LANDING. R & R NR 1 AIR CYCLE MACHINE IAW AMM 21-51-03. OPERATIONS CHECKED GOOD. PERFORMED ETN-EM-72-034 R9. NO DEFECTS NOTED. NO VISIBLE SMOKE OR BURNING SMELL IN CABIN OR COCKPIT NOTED.