Horizontal lines on screen XPS 17 (L702X)

Hi!

After 3 years of wonderful use there was a problem.
The horizontal lines at the bottom of the screen.

First there was one, an hour later the second, and the next day they have a lot (height 115 pixels).

I have 2 suspects: the video card and the screen. 
Maybe someone had a similar problem? 
Help please.

Laptop configuration

XPS 17 (L702X)
CPU:Mobile QuadCore Intel Core i7-2670QM
Intel Cougar Point HM67, Intel Sandy Bridge
DIMM1: Nanya 4GB DDR3-1333 
DIMM2: Nanya 4GB DDR3-1333 
Video: Intel HD Graphics 3000
Video: NVIDIA GeForce GT 555M  (3 GB)
Screen: Chi Mei N173HGE (Dell HC9GK)  [17.3" LCD]

Thanks in advance,

Val Mazur