The screen at first when I connect it to battery shows about 4 dashed lines, no button I press changes this. After I 20 minutes with it turned on it eventually says CODE then allows me to enter my 4 digit security number. The only button that makes any change to the screen once the code has been entered is the 'back' button, or left direction as you look at it face on, this makes all the code entered disappear and the screen goes back to how it was at start up.