Grid like backround

[Ohsweetadeline]

Randomly my phone will get a grid like backround making it so that I can not use it at all it comes and goes as it pleases it will also flash into negative coloring... Not sure if this is an easy fix or if my phone is shot sometimes it last seconds other times it will last for hours someone please help!!

 

[blueroom]

Take a screenshot, if the grid shows up in the photo post it here, else it's a hardware problem and needs to be serviced.