Is the screen full of vertical lines? It sounds like your Tcon has gone faulty but...there is hope. Firstly, only if you are competent with electrics follow the procedure bleow, else get a qualified tv engineer to inspect your tv.
Remove the back cover on the tv.Looking in from behind, check the power supply which is the board connected to the mains power lead. Check the capacitors, making sure none of them have bulging tops.These are the components shown below.

The caps shown below are an example of faulty caps, with their tops bulging.
This model of tv is prone to this condition, and if you have any bulging topped caps, replace them.
Next check the Tcon LVDS lead connection. The Tcon is the board located top centre of the screen and is enclosed in a metal plate.It has a lead connected to it that goes to the main board. Clean the connector at the Tcon.Be very careful though because the connection is fragile. It can be removed by gently squeezing in either end of the connector and gently pulling outwards.If these procedures are not successful, replace the Tcon.