Restoring of iPad using recovery mode fail due to 15 minutes timeout

Solution 1:

This constantly happens to me and people I know.

  1. Download the .ipsw file - links to true Apple Software are listed at https://ipsw.me
    [files hosted by Apple, the site simply makes the files findable, as Apple doesn't publish the locations]
  2. Place the file in ~/Library/iTunes/iPad Software Updates or ~/Library/iTunes/iPhone Software Updates depending on device.
  3. Launch iTunes & connect your device
    The ipsw ought to be discovered automatically.
  4. Follow the on-screen instructions

ipsw.me has links to all iOS versions, however generally only the latest is still being signed by Apple & will therefore be the only one that works for a restore.