Chosen Solution

Background: My IPhone6 (A1586)’s screen damaged, and Home key is not functional, so I tried to use another unused Iphone6 (A1589)’s screen and home key to replace, everything work fine except the Touch ID not working (because IOS system detected a Touch ID is not associate with this iPhone). I think that is fine because at least I can press the home key. But after two days the iPhone’s screen suddenly blank, and never able to power on. I am quite sure that the battery is ok and about 94% power quantity. I searched the internet and it is said that IOS will make the phone non-functional if detect a Touch ID that is not associate with it, in order to protect the data in that phone. Is that true? If so why it is after two days? Then I tried to remove the screen and replaced a new home key which don’t have a Touch ID. It still not able to power on and I tried to use iTunes to recover the system. I press and hold the power on key and home key for more than 10s and released power key, after a few seconds iTunes detected a DFU mode, then I load the downloaded latest ipsw file, but ITunes stop at waiting iPhone to enter recovery mode, and reported error of 4005 after timeout. It means the phone can enter DFU mode but can’t switch to recovery mode during reprogramming ( iboot not functional?) What I am quite sure:

  1. battery and screen is connected well and no functional problem;
  2. screen can never be lighten. When I plug in cable it can’t display the battery icon, when I enter DFU mode it can’t display the iTunes and cable’s icon.
  3. no other physical damage.

Does anyone have experience/knowledge about such problem and can provide some suggestion that I can try to fix the problem?Thanks!

If you are in recovery mode, the screen will not light up. You can install a tool like 3uTools and it will tell you if the phone is in recovery mode and give you the possibility of exiting this mode. If the screen still doesn’t light up, then this could be due to a blown backlight filter. When you replaced the screen, did you have the battery disconnected throughout the whole procedure? Failure to do so can cause logic board damage. to be certain, shine a bright light on the screen when you connect it to a charger or iTunes enabled computer. If you can see a dim image, then the backlight filter on the board is probably blown. As for error 4005, that is a more serious issue. Try to get the screen issue resolved first.