ps2 dvd copy

[hktrj]

Hello All,
I currently own a Jap PS2 Ver 30000 pre Mod to direct boot. I can boot all backup games, and Japanese game but yet can't do anything to US original games. I try to make backup of the PS2 US ver games which I bought with my dvd-r and put it in my PS2, but it still doesn't boot. Does any body know a way out? I don't know what mod chip is in my machine, since I bought it premod, and the person said it can boot US game.

Thanks for all your help

hktrj