Kobo Touch screen fading

Good morning. I still have a Kobo Touch. Recently, the screen of my N905C model started to fade and there are more "ghosts". It's like the screen is becoming all white. Changing the font settings is of little help.

I tried recharge the battey, and thanks to the kindness of people in this forum, I reinstalled the image. But the problem persists.

Does anybody have any idea on what could be the problem? I phoned Kobo Service but since the warranty expired - I bought the device in January 2013 - they could not help. I guess it's a hardware problem. :bulb2:

Thanks in advance :thumbsup:
Adriana N. da Silva