Skip to main content

Fourth generation iPhone. Repair is straightforward, but the front glass and LCD must be replaced as a unit. GSM / 8, 16, or 32 GB capacity / Model A1332 / Black and White. This page aims to help users troubleshoot, fix, and seek help for the iPhone 4.

2375 Questions View all

My phone won't start..getting error 21 when restoring

Hello,

Since yesterday i can no longer start my phone unless i connect it to the cable , and it enters in restore mode automaticly.

I tried to restore it , but keep getting error 21 when doing so.

Can you help me with a solution that does not involve me taking the device to a service?

Answered! View the answer I have this problem too

Is this a good question?

Score -1
2 Comments

is this a jailbroken phone? you sometimes get this error from apple not recognising your firmware. You'll need to either use iReb/tinyumbrella etc to reboot.

by

It is a neverlock version .

Also since yesterday the back of the phone get's very hot.I am huessing it's the battery.

I will try what you said and get back ...

by

Add a comment

1 Answer

Chosen Solution

try this from techarena

Error 21 Unknown

Mac, Go to ~ / Library / iTunes /. In the Finder, you can choose Go> Go to Folder. Type or paste the path name above and click OK. - Delete all files in the iPhone Software Updates and Device Support. - Try to restore the iPhone again.

On Windows, these files are located in a hidden folder. To view these files in Windows Explorer, you must select Tools> Folder Options, click View, then select "Show hidden files and folders.

In Windows Vista, follow the instructions below: - Go to Start> Computer> Local Disk and type the following path: C: / users / [yourusername] / AppData / Roaming / Apple Computer / iTunes / - Delete all files in the iPhone Software Updates folder and Device Support. - Try to restore the iPhone again.

In Windows XP, follow the instructions below: - Choose Start> Run, then type C: / documents and settings / [yourusername] / Application Data / Apple Computer / iTunes / - Delete all files in the iPhone Software Updates and in Device Support.

If, despite these recommendations, you still have this error, make sure you have the latest version of iTunes.

Try using a USB hub.

Was this answer helpful?

Score 1
Add a comment

Add your answer

Haiduc will be eternally grateful.
View Statistics:

Past 24 Hours: 0

Past 7 Days: 0

Past 30 Days: 0

All Time: 3,227