when i had a ps2 i always had bad luck with 9v's and i built a external power pack from a rat shack adaptaplug, 3' adaptaplug cable and 9.6v rc pack
cheap and easy
i have a 9v rc pack and charger you could have for like 10$ + shipping, bet i even dig up the cable part that plugs into the rc pack to attach the rat shack cable u could have too