I have a 83 + and when I turn it on the screen had black dots and lines all over it. When I push the buttons I can read what it says. I tried updating the OS and it did not help. When I push the del button and put the last battery in it gives a warning about updating the os. This warning is perfect looking. There are no dots on the screen and all the text looks great. When I turn it off and back on it goes back to the black dots on the screen.