I posted an old iPhone 4 to my sister (I'm in Australia; she's in Thailand) which was working fine both before and after she received it.

Recently it has started cutting off while being used - especially when using data - and saying there's 'no reception'. This was happening every couple of weeks.

My sister has been restoring the iPhone through iTunes each time this happens, which had been resolving the problem until it came back again.

Unfortunately now though it is no longer restoring through iTunes, and showing this error message:

The iPhone "iPhone" could not be restored. An unknown error occured (-1)

The iPhone "iPhone" could not be restored. An unknown error occured (-1)

Obviously this is a pretty unhelpful error message. This Apple support page covers the next steps for most error types, but it appears that the error number -1 is an error in and of itself!

The phone is now stuck on the usual restore screen:

Usual iPhone restore screen

What steps could we try to resolve this? Or is it likely that the phone is just too old and is suffering from software designed for newer iPhones? In case it is relevant, the phone has never been jailbroken and I (and my wife) have always been the original owners. It is a 4, not a 4S.

  • Although it was never jailbroken, do you know if you had to ever do anything special when restoring it to preserve the baseband (to keep it carrier-unlocked)? Because I've never heard of error -1 happening in any case except for baseband preserving. May 9, 2016 at 19:55
  • @AndrewLarsson Hmm good question. I don't recall, as it's been quite a while since I ever restored it. It was carrier unlocked but probably wasn't when I first got it. Are you saying it's possible that restoring it would also restore the carrier lock?
    – Tim Malone
    May 9, 2016 at 20:39
  • Yes, it's possible that would happen. I haven't done baseband preserving in a long time, so I might not know the best way to solve your problem. Your next-best bet might just be to just exit Recovery Mode and hoping your cellular doesn't have problems again. May 9, 2016 at 20:55
  • Oh, I didn't realise recovery mode could be exited - thought it was restore or nothing. Have Googled and will try it. Thanks for your help regardless!
    – Tim Malone
    May 9, 2016 at 21:11
  • It used to be restore or nothing, but people have made tools to exit it for you. TinyUmbrella is the best one I've used. May 9, 2016 at 21:19

1 Answer 1


If it auto shutdown too often and require restore everytime like that then you should consider the phone is too old. Hardware especially its memory start malfunctioning. As end user, there is nothing you can do, sorry :(

But repair services does, hehe :D

  • Thanks for the answer. I'm hoping that an iPhone 4 isn't yet 'too old' and there's a way to get past this problem - or at the very least to be able to understand it further. But in the end you may be right - I just hope not!
    – Tim Malone
    May 13, 2016 at 21:53

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