Laptop Asus N76VB Nvidia Geforce GT 740M artifacts?

Hello all

I have a laptop from my friend to fix it.
I just wonder what is this kind of artifacts which one I uploaded.

GPU artifacts:
http://ift.tt/1GBeuIA
http://ift.tt/1GBesjT

It's happen on Laptop N76VB which one has got two graphics cards.

Intel GPU HD 4000 works fine but...

Laptop Asus N76VB Nvidia Geforce GT 740M artifacts?

Laptop Asus N76VB Nvidia Geforce GT 740M artifacts?