Bought a Diamond Vision 803-04 from Walmart. It's a region 1 player.

Plays some region 1 discs, when usually says "wrong disc" when most discs are loaded.

tried the hack listed on this site, but when I press "setup" and the hack code, it does not lead me to a region listing.
I'm new to this, and am not sure I'm using the hack correctly, or maybe the player is defective.