What was found
CABIN ODOR: VERY STRONG BURNING SMELL INSIDE AIRCRAFT AT 5K FT... THE PASSENGER SMELLED IT AS WELL. AFTER ENGINE SHUT DOWN, AE OPENED THE REAR EQUIPMENT BAY AND ALL INCLUDING LINE SERVICE SMELLED IT AS WELL. CORRECTIVE ACTION: PER FRS RECOMMENDATION, REMOVED AND REPLACED ENVIRONMENTAL CONTROL PCB NF204 WITH A CUSTOMER SUPPLIED INSPECTED PART. REMOVED AND REPLACED HEPA FILTER WITH A CUSTOMER SUPPUED NEW PART. PERFORMED SATISFACTORY CHECKS OF ENVIRONMENTAL CONTROL PCB NF204 IAW CE-680A AMM 24-60-40 AND 21-70-10.