Hi, I replace some screens on friends iPhones but my last 2 screens from a new supplier did not work ? His screens had a...

Hi, I have done a few iphone repairsbefore but am having trouble getting the iPhone glass screen and digitizer inserted...

I had the Black Screen issue then flickering lines. Did all the solutions posted on many sites and none worked. Have got a USB self booting updated to High Sierra and then when loaded tried UNSELECTING Automatic Graphics Switching in System Prefs. My mackbook Pro 2015 is now working again without screen issues. Hope this helps.