Chosen Solution
When holding the power button nothing comes up on the screen, the phone does not vibrate when hitting the switch or anything, so it seems like it is dead. So i plugged it in my computer, and instantly it was recognised by itunes, and i am currently restoring the device. I have no idea however why the device is not turning on at all, the screen is fine, and i’ve checked all the connections.
Is this issue following a repair? If it is, you may have a blown backlight circuit. One way to test for this is to shine a bright light on the screen when you connect it to iTunes. If you can see a dim image, then the backlight does not work. This could be screen related or logic board related. If the device was repaired, then this can happen when the battery is not disconnected prior to removing the screen. If the phone was never opened, you will need to try a known-good screen to see if the problem is with the screen or logic board.
