Here is my story :
First of all, i bought a HTC One M8, one day was very rainy and my HTC M8 was in my pocket, i was very wet and the humidity goes on my M8.
Ok after that arriving home, i saw my screen black, no more backlight, then the backlight screen flashed i was thinking it come back but no never came back.
I sent my HTC (under warranty) to HTC.
They said it's not under warranty cause it's water damage...
I was very angry about that, cause my phone was just in my pocket.. They propose me to pay 600 USD to repair the phone, i said no i don't want to pay the cost of the phone just to repair it.
They send it back to me, i ordered a replacement screen on a very known website for 100 USD with all the tools, i changed it, charged the phone and, started the phone, and backlight is always black, i can see the picture through sun but the backlight don't work !!
Can someone explain me where is the Backlight on this phone ?? Is it a mainboard problem ?? It can't be the screen...