ferguson ldvd 220?

i have a portable ferguson ldvd 220 dvd player which i have had for a while but not used . got it out to use for my son to find that when playing a dvd the picture disappears but the sound is still there. if i preess the the little button at the top where the screen shuts down the picture returns. when it disappears you can still see a ghosting effect on the screen why is this/