Itunes error (-1), basically occurs due to changing of baseband of the phone,means the carrier of the phone unlocked by changing the baseband of that iphone. So, when you face itunes error -1 it does not means that the iphone now can be restored easily with itunes, so -1 error is completely a hardware problem so you have fix it with hardware solution.,

When you use iTunes to update or restore your device and you see an itune error (-1) code alert, learn what to do………….

  1. Disassemble the touch screen and digitizer properly
  2. Remove all the  cables from the board
  3. Then open the screw and take out the board
  4. now find the basband area of the phone
  5. Then give some heats over the phone and try to restore the phone if works then no problem , but if not then,
  6. change the baseband of the phone with any other phone (in my case of iphone 4/4s/5, I tried with these 3 phone with nokia’s 3310 baseband) its worked completely .

So this is the only solution to fixed the itunes error (-1).

***** DO AT YOUR OWN RISK AM NOT RESPONSIBLE IF PHONE GETS BRICK******