Problems updating iphone 4s
If that doesn't work, plug your device into a power socket and let it charge for around 15 minutes.
After it's charged, reset the device again and hopefully it'll return to a working state.
The update will erase all your data on your device, so you’d better back up your i Phone with i Tunes or i Cloud in order not to lose the important data during the update. Click device button to the left of the i Tunes Store button in the top right corner in i Tunes. Click the name of i Phone and choose files you want to backup in the left sidebar. Or right-click the files you want to backup, and choose to “Transfer to Step 3.
It also helps users backup i Phone, i Pad and i Pod touch files to computer with no efforts.
Next, open up i Tunes, select your device and click 'Summary' then 'Check for Update'.
The i OS 9.3 update should then display, enabling you to update through i Tunes.
If the user finds out that his/her i Phone is bricked, and never gets recognized to i Tunes, he/she ought to try the device on another computer.
If the bricked i Phone still can’t be restored, the user will need to send it to the Apple Store to get it fixed.
After i OS 9.3.2 update, many i Phone users have encountered the problem of restoring i Phone.