that's not a lot of info to go by. what did you do prior to getting this screen? since when has this screen been showing? is it rooted? did you do low level stuff with it, and if so, did you do it through a computer or on the phone directly?
the first thing you would want to do is to check if you can enter recovery mode (stock will do if you don't have an aftermarket) and see if you can do something with that, like, say; factory reset.
the next thing you could try is to first backup your flash, and I mean from sector 0 to EOF, and a second backup per partition, then flash a stock rom you could get online.
I WOULD preffer to just diagnose the problem and fix it non-destructively but phones and their OSes are not built to accomodate repair beyond changing the screen/batery and resetting/flasing the ROM
P.S. throw in the chipset type while you're at it I.E. MTK or QLM