Screen stays white after the calculator is started

When I press the "On" Button, the calculator screen becomes black for a very short time and then becomes white. There is nothing I can do except pressing "2nd"+"On" (Off) or resetting the calculator ("Hand"+"2nd"+"On"). The reset makes the screen blink like the "power on". The "hard reset" (remove all the batteries) also doesn't help.
The screen seems to work because the white that I can see if the Voyage 200 is turned off is not the same as the white when it's turned on (it's a bit darker). The keyboard also seems to be ok (reset works). Perhaps the connection between the board and the screen is the problem.