Getting codes to Work

[gdog]

I have entered the cheat codes but for some reason I don't hear a sound and I can't get any of the codes to work. Any tips or idea's?
I also am trying this on the main screen where it shows world tour, tournament, exhibition options. Help what am I doing wrong?

Thanks

[Vipershark]

how about telling us what game it's for, and maybe we can help you?

[gdog]

Sorry yeah I guess that would help. Its virtua tennis 3 on playstation .

[gdog]

virtual tennis 3 for playstation 3

[mcdogit]

is your sound working?