I shattered my display.
I was very nervous trying to replace my own display. I read through all the instructions a few times and then started on my odyssey. The screen popped off very easily and everything went pretty smoothly. I was trying to be so delicate that nothing was coming off (battery connector and cables). But then I got a little more courage and realized that this iphone is not as scary and delicate as it seems. You can use a little force. But you do need to be careful with the home button rubber gasket. And you need to be aware that the home button flex cable that stays with the display panel is not glued down. You need to separate it with your fingers and pry them apart from one another so you don't actually tear the cable. When I went to turn it on, it stayed blank. I was really worried that I did something wrong so I uninstalled it and reinstalled it two more times with the same results. I troubleshooted everything. Did a hard reset. Charged it. Connected it to my itunes and nothing changed. I then decided to reinstall my old screen to see if it was me. I wasn't me. The iphone turned on and everything looked perfect. Except for the shattered screen. I called customer service and they said it's likely that the backlight was faulty on the product I purchased from them. So it's now one week later. I received a replacement yesterday. Installed the new screen. It took me only 20 min and it turned on perfectly! Yay!
Sometimes it's not you. Sometimes you just get a dud. Also, don't get rid of your shattered display panel. Keep it because you may need to put it back on to troubleshoot. I was prepared in advance. I made post-it notes and put them next to tiny bowls. That way when I unscrewed everything, I had a home for it. It kept me very organized and things went very smoothly as a result. I used a piece of packing tape on my shattered screen so that the suction would lift the screen just enough so that I could get the flat end of the spudger under the screen. You don't need to use that much force. It come up pretty easily.