I'm wondering if anyone else has experienced these exact situations, and more to the point, whether anyone has managed to wriggle out of them. Among other things, I'm a hobbyist repair man. People hand me devices, I fix them and hand them back. A lot of these are phones, tablets and whatnot with cracked screens. Occasionally, I get handed an iPhone which will show the "plug me into iTunes" message, but always fails to restore. These phones have an additional quirk in that they will only power on when connected to a computer or charger. Typically they enter this state after the owner attempts to update them (eg because iOS downloaded an update automatically and prompted them to install it). The phones are used by average people from various backgrounds, and have never been jailbroken or similar. Before jumping to conclusions, please consider all of the following: Restoring the device does actually appear to complete successfully, but when the phone reboots at the end of the process, it goes right back into its previous state and refuses to boot up. The computer, which is waiting for a booted phone to appear on the end of the cable (so it can activate it), eventually throws an error 21 or similar ("I can't find the phone"). It doesn't matter which lead, computer or network is used to attempt the restore (unlike in most other "restore failure" cases, where you'll probably find your cable is to blame!). Others have been tested (including different iTunes / OS / iOS versions), and I can immediately unplug the phone and restore a different device of the same model without issue. Likewise, a restore from DFU mode acts the same way. Although the phone will not power on without a cable attached to a power source, the amount of power stored in the battery is irrelevant. In fact, I can take the logic board out of the phone and place it into a different device of the same model (effectively switching battery, camera, dock and all other components) and it'll malfunction in the same way. I can then take the logic board from the other device and place it into the affected phone's body, and it'll work perfectly. Thus far over the years I've encountered this problem with iPhone 4s, 4Ss, and 5s, starting with iOS 6. Never an iPad or iPod, oddly enough. I consider affected phones to become "spare parts". I'm curious as to whether anyone else is familiar with these specific symptoms, knows their cause, and ideally, is aware of a way to salvage the logic boards.