camera,ear peace, display error

Hi I have an iPhone 6.... I changed the display, the problem is that the display becomes black randomly.

I have changed two displays with the same error .... Now I find error that the face camera and earpiece don't work ..

I test a display from my own Iphone 6 and then the camera and the ear peace work

so it not i logic bord error.

I ordered new camera .. to day but I don't know if the

randomly black display error is sovled

Is it someone who had the same error

there the camera is corse the display becomes black randomly .. ????

Hi the screen randomly goes black .

I have tried to clean connectors and tested 2 screens

but still it don't work it sometimes start to blink after 10-20 min

then it goes black. If i push power button it shout off

i can hear the click, then it wake up the screen home or power button

please help.............