Display not working, touch does work

I had a customer bring in a samsung galaxy s6 that had a black/blotchy screen. He claims that it had not been dropped nor had any water damage (water indicators proved his story). I replaced the lcd and it worked perfectly for me. Later that day it stopped working completely. The touch screen still works as I can hear the screen making sounds it makes when it unlocks. I took the phone apart again and checked the connectors and it all looks like it should work. I didnt know if theres anything else that can be done before I put in the new order for screens.