sounds to me like your tama is debugged.
to fix it just take the back cover off then there should be 4 tiny screws in each corner , take those off too. you should then see the circut board. get an eraser and where it says DeBug. there will be a circle underneath it. with the eraser rub the circle in the middle where the circle is divided and put the tama back together it should then work fine and you will be able to put passwords in. that happened to my V3 as well so i know what was going on.
