How can I restore my iPhone 4 so that it will work again?

[iMore Question]

I try to update my iphone 4 to ios 7.1.2,i didnt know the iphone 4 from japan cant update for this version..now if i turn it on have this itunes plug in..i tried to connect in my computer in itunes but its not working..any idea what should i do?pls help me..thanks

 

[Just_Me_D]

Put the device in DFU mode (instructions below via the link), connect it to iTunes, and when iTunes detect that the device is in recovery, select to restore and update it. Make sure that your computer is connected to the internet.

DFU Mode - The iPhone Wiki

 

[KennyMcCormack]

Not sure with international variants, but whenever I restore older AT&T iPhones, I need to make sure there is a SIM card (doesnt have to be active) installed. Otherwise, you get to the activation screen and can't get further.

 

[Rizalyn Feguerra]

Thanks,but i still cant restore my iphone 4..the itunes cant detect it..

 

[AgentHeracles]

Do you have access to an Apple Store in close proximity to you? If you do, then I suggest going to one and seeing if they can help in any way.