Screen goes black after locking the phone and won't turn back on.

So, I replaced the screen on my phone and it work when I powered it on.

But after i pressed the lock button the screen went black and it won't turn back on again. The only way for the screen to turn on is to force reboot the phone.But then the same problem , screen goes black if phone locks. Even with the screen black the phones works(I can hear notifications).

The exact same problem happened with an Iphone 5s I had..

Could it be a faulty screen?