I Can See Only Half Of My Display On My Coby 300 2g Mp3 Player.

I really hate to say it but it can bo only a couple things, the LCD display on those unit is not a pressure type it is a solder type so either the connection to the PCB came loose and needs re-soldering, or and this is the far more likely problem, the unit uses a LCD display. which by design is 2 thin layers of glass with the pixel grid screen printed onto both the front and back glass plates and a kind of clear conductive liquid that depending on the signal between the plates will be clear, opaque, red, blue, green and all shades in between, giving a picture with a polarized filter on the front and a translucent white on the back with a light source behind that so you can see the colors and shapes.

    However because these screens are so tiny and needs more than a single layer, they tend to be very very thin and because they are glass or in the more expensive ones a thin crystal instead of glass, that the smallest shock by dropping it or sitting on it or anything else that could break the material and when broken, even if it is only one of the plates, the conductive screen print grid on either plates will prevent the signals to create the picture on the broken plate.

  Sorry but I would lay money on the broken screen because if just the back plate is broken you cannot see any crack from the front.

  Sorry about the bad news.