Hi.i can't split the screen on the ps3 when playing mine craft.to add a second player.my settings must be wrong somewhere?

Hi .i have both cables plugged in .ive tried taking the colour one out then I get no picture.will I need to reset the ps3 after I have changed the cables.sorry its my sons ps3.i have no idea about it Hi .i have both cables plugged in .ive tried taking the colour one out then I get no picture.will I need to reset the ps3 after I have changed the cables.sorry its my sons ps3.i have no idea about it