Try using another computer to restore it.
If it doesn't then bring it to Apple for replacement.
Okay I will try it.
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Its a software for PC. It allows you to access your device's file system via USB if you have afc2add installed from cydia on iOS 7
So I should already installed afc2add, but i'm sure i haven't installed this thing on my ipad. If I could access to my device file system with iFunbox, can i fix it then.