I read through this thread. I didn't think it was possible, but when you can't get anything to appear on the screen and the iPhone keeps pulsating and chiming at you, you'll try anything. So I held both buttons to reset, and worked like a champ. Also, I learned not to buy knock-off screen assemblies. Buy OEM replacements. I had to buy 2 non-OEMs to get a good replacement. Siri wouldn't work, dim to talk on the phone didn't work. What a mess.