Paintball gun leaking co2 in gas chamber 05 spyder sonix?

My 05sonix is leaking co2 in gas chamber.when I screw on the co2 tank it automaticallys spews out co2. I replaced all the o rings but still no sucess. What's wrong with it and what should I do? Do u know any shops tht could fix it? There's a academy in my town.