What was found
BURN RUBBER SMELL IN CABIN AFTER RUNNING PACKS OFF START CART FOR EXTENDED PERIOD.DETERMINED SMELL ASSOCIATED WITH RUBBER HOSE CONNECTING CART TO AIRCRAFT. AIRED OUT A/C THEN PERFORMED LEVEL "A" DECONTAMINATION OF ECS IAW A321 AMM 21-00-00-615-802-A. REPLACED CABIN RECIRCULATION FILTERS AND AVIONICS VENTILATION FILTER. FOUND CONTAMINATION ON AVIONICS VENTILATION FILTER REF 21-26-43. RAN APU + PACKS. NO UNUSUAL SMELLS, A/C COOLS AS NORMAL. A/C OK FOR SVC. (LP# 4139889)