Hi,
If the pictures that you take are OK then most probably you have a faulty LCD screen. LCD screens cannot be repaired, they need to be replaced.
Here is a link to a video which shows how to replace the screen. It is in German but it is self explanatory as to what you have to do.
https://www.youtube.com/watch?v=4Rxsaz-iyFE
The LCD screen is available on Ebay. Here is a link to just one supplier to give you an idea of the cost . There are others.
http://www.ebay.com/itm/Samsung-S630-S730-S750-LCD-DISPLAY-SCREEN-MONITOR-NEW-/330496835546