Aporte original por: FIXiPhone361 ,
This worked for me a few times. Black screen with new part = that is a bad part. Replace the original cracked screen if possible and perform a soft reset until the apple appears. Once the phone boots up shut it back down and try another replacement part. If it fails again repeat the process. NOTE: When replacing the original screen and cannot get the apple logo to appear with a soft reset the logic board may be damaged. A good idication of this is if you get the repeating charge sounds/vibration when plugging in the phone = red ring/blue screen of death! Good luck!