messed up playback on toshiba dvd/vcr combo

We have a Toshiba DVD/VCR combo player at work. It worked fine initially, but now when I try watching a DVD it fades in ad out. The picture quality is fine one second then gets all dark and ugly the next. I thought it was the progressive scan thing(not sure how exactly it works but I know it sometimes help) and it still does the same thing. I asked around and no one messed with it(supposedly). I know some VCR's do this when trying to record from a DVD player, but since this is a combo player I figured it wouldn't do it and like I said it wasn't doing it before. Thanx in advance for the help.