Screen isnt turning on? try the order of operations below that my technicinans all follow!
By following the steps below, you agree not to hold myself, or the website responsible for any damage to self, device, or surrounding objects, that improperly handling your phone may cause. These steps will also assume you have the required tools to do repairs, where as else, it would make no sense to ask for instructions.
1) Hard Reset: Hold the home, and lock button down together for 15-20 seconds, or until you see the apple logo. if you get the apple logo, great! if not, continue
2) Data restore: Plug the device into the computer. (preferrably one it has been plugged into before) make sure the device is recognized by USB. check what the device reads as on iTunes. If it gives you the option to restore the device up front, then do so immediately. should it read fine as a phone, then continue
3) Loose connectors: Disconnect the screen, clean the connectors with Isopropyl 99% rubbing alcohal, and a new toothbrush. Then reconnect the screen. Should this fix the issue, great! if not, continue
4) Excite The Battery: Hit the + and - of the device with an external power supply for approximately 30 Seconds to 1 Minute. (This power supply MUST be of the proper voltage and amperage of which the battery will accept, otherwise injury may occur. these Specs can be found written on the battery itself)
The next steps require parts, and will not be free of charge
5) Check the board for physical damage: Scan the board (Preferrably under a 10X+ Microscope) for cracked, chiped, blown, or missing components. replace any problmatic components.
6) Battery: Replace the battery, if this fixes your issue, Great! if not, continue
7) Screen Replacement: Replace the display assembly. If this fixes your issue, great! if not, continue
8) Logic board replacement: You will need to replace the logic board in the device. this will fix your failure.