Nikon coolpix L20 image screen just shows a bunch of lines
the image screen just started showing a bunch of colored lines so cannot take any pics.
The L20 is rather small camera (even by compact standards), measuring 96.5 × 61 × 29 mm, it weighs almost 135 gm (including batteries and memory card).
Was the camera dropped just before the screen developed the problem?
Try taking a picture and then download it to a computer to check if the picture is OK or whether you have a distorted or black image. (I realize that you cannot see what you are taking).
If the picture is distorted or black there is a problem with the ccd sensor or the motherboard or both.
If the picture is OK then hopefully it is just a problem with the LCD screen.
Here is a link to the ifixit Replacing Nikon Coolpix L20 LCD guide.
Here is a link to suppliers of the replacement screen.
It is not a recommendation to use any of them. It is shown to give an idea of the cost of the part. There are other suppliers available online that may suit you better. Just search for Nikon Coolpix L20 LCD screen part to get results.