display only show backlight after screenreplacement.

hi everyone ,

im brian, i work in a repair shop.

i got the next issue with a Huawei P8.

i replaced the entire screen (lcd + digitizer) and after i start up the phone i can see that the screen lights up but doesnt show annything, so bad screen i think.

tried another one same results. bought another one but this time full screen assembly with the housing , ---> ofcourse same result...

annyone knows what the problem is? would be weird that i ordered 3 bad screens (from good companys)

anny 1 got ideas ? i would love to hear them.

thanks alot!