Put your device into DFU Mode. Ask other users about this article.
Method 7: Confirm that FoneDog toolkit was able to detect your device. As with all devices, no matter who the manufacturer is, unfortunate errors may occur out of the blue. Mar 17, 2014 2: I had opened up the phone and noticed the battery connector had now became loose and has now detached from the logic board, upon doing my own research on Error code: If not, please read on to the next method.
Ask a question Reset. Doing this via iCloud would be optimal. This website is not affiliated with Apple.
Make sure that your USB cable, computer, and network are reliable. If you need any more help you can always ask. Connect your iOS device to your computer and have iTunes ready. We have come up with an in-depth solution to the iPhone black screen issue in this post. Select 'Check for Updates. Your iOS device will once again be automatically detected. However, fret not, we will show you how to fix that iPhone Error 21 easily and effectively and get back to leading your iPhone engrossed lives!
If you see one of the errors below, your computer might not be able to connect to Apple servers or your iPhone, iPad, or iPod touch: As previously mentioned, there are several causes to why the error appears, so do not be discouraged if one method does not work, simply try the others! Hopefully, this had done its job, but once again if not... One of the biggest concerns you probably have while attempting your restore and trying to fix iPhone Error 21 is whether your data is safe.
Look for a device cable and disconnect it then reconnect it. Connect to iTunes.
Launch iTunes Step 2: Hope this helps!!! At times, the fix required can be as simple as this. Repair various iOS system errors back to normal status.