iPhone 5S stopping at updating firmware during software restore in iTunes. Phone now stuck on 'connect to iTunes' screen.

OK, firstly, thanks for replying. But not really any new info here beyond Apple's fairly nondescript form answers. Please re-read the post 😉

It's an Error '1' , so I'll run through answering some of the points that Apple say it may be (I've read your copy/paste info about 20 times in the aptly infinite loop of 'help' pages on Apple support haha) :

1. There is no security software installed on the machine I've been testing this on. There is nothing preventing communication with the Apple update server and indeed the software update has successfully downloaded, because the issue only arises during the firmware update stage after the actual iOS update has been completed and the install verified successfully by the update server. The router has been specifically set up to ensure there are no barriers with all traffic between the WAN and the individual machine on the LAN being routed through in both directions for all of Apple's port numbers and services.

2. I have attempted perhaps 40 or more restores while connected with a cable, computer and network I know are good. Plus another 30-40 times with another computer I know to be good on the same network and tens of times with two other Macs and one Windows PC on two other networks all of which I know to be good.

3. There is no security software barring communications between the device and update servers (see point 1).

4. I've tried to contact Apple support, but unfortunately I can't supply them with a serial number because: (A) iTunes is displaying the serial number for the iPhone as 'N/A' (presumably because the installation hasn't completed) and (B) I can't access iOS on the phone to retrieve the serial number (because the installation hasn't completed). No serial number, no Apple support. Which is why I'm asking here.

There's no firewall running. There's no antivirus running. There's absolutely nothing blocking traffic to/from Apple's update server. Indeed I can run software update on any of the 15 Macs and half dozen or so other iPhones in this office and they all connect successfully The issue isn't network related - it's isolated to this device.

The phone has never been jailbroken. It's been owned from new - it's not even been unlocked from the mobile network operator and is still under the original contract. It's approx 12 months old. Neither have any of the 4 Macs and 1 Windows PC I've now tried to restore the iPhone through been used for jailbreaking iOS devices. Two of them had never even run iTunes before.

So back to my original question - is there any way to reformat the phone from the command line so that iTunes can then restore the software from scratch and the data from the iTunes/iCloud backup?

Surely there has to be a way into the underlying filesystem for such situations (software update corrupting the phone) where a limited GUI approach is hopeless? Or is it truly bricked?

Sorry - to clarify, I'm downloading the update THROUGH iTunes. iTunes downloads the software, extracts it, verifies the installer to check it's extracted correctly (presumably against an MD5 hash checksum), installs it, verifies the installation (again probably a checksum to make sure it has actually installed) and then runs a firmware updater in this instance. It's at this point that the installer fails through iTunes.

I thought perhaps the installer file from Apple's update server was itself damaged - it's not unknown and I've seen it happen before, albeit very rarely. With that in mind I did hunt out a standalone installer file and downloaded that to give it a try (it opens iTunes and runs the installer within the iTunes environment, so essentially it's the same as downloading from the remote server), but again the same results.

It's not the software, the network or the download process as far as it's possible to verify without having access to the kind of diagnostic tools Apple invariably have. The installer appears to have corrupted something within the phone's firmware and I need a way to wipe it and start again, because the normal restore routines just don't work. Which is why I thought there must be a way through the command line into the base filesystem to delete and create volumes on a device. It's possible with any other external 'drive' so there must be a way with an iPhone, unless it's something that Apple have specifically locked down to stop people tinkering, which wouldn't surprise me in the slightest.

::ADDITIONAL INFO::

And yes, the unit is in DFU mode. When plugged in, iTunes detects it as a device in Recovery Mode.

You see my quandry? None of the 'officially sanctioned' methods work, but I'm pretty sure the hardware will still function if there's a way to wipe the corrupted software and start the restore afresh. But only IF there's a way. :/

Ah, righto, I'll give it a go when I get back into the office in the morning. I followed the steps to put it into DFU mode, but it seems if you hold the home button for a fraction too long (so the Apple logo appears) it's actually starting into Recovery Mode, not DFU. I should have access to the machine it's been synced to tomorrow as well, so I'll try to find the serial from the backup. I had it plugged into that machine earlier today and the serial wasn't showing up under the usual iPhone info screen, but never thought to check in Prefs>Devices. Cheers for that - I'll post back on the morrow to let you know how I get on. Wish me luck! 😀

OK, follow up this morning. I've managed after about 20 attempts to get it into DFU mode - there's literally about half a second difference in holding the sleep/wake button between it going into DFU Mode or Recovery Mode!

Anyway, finally got it into DFU, connected to the PC it was synced to. I'm getting a serial number at least now, but when it runs through the restore procedure (the only option given) it drops out after about 20-30 seconds with the error 'The iPhone "iPhone" could not be restored. The device cannot be found.'

Weird. It's like iTunes is unmounting the iPhone volume to restore it, but because it's no longer mounted it can't find the device. Any other ideas?

I'm way ahead of you here. Exactly my thinking in the early stages. Tried it on a couple of MacBook Pros, an iMac, a MacMini and a PC laptop. Each time straight into the USB on the machine, no hubs, no other devices. I even tried disconnecting the mouse and keyboard from the MacMini to give it as much oomph as possible to the iPhone and then controlled the Mini via Screen Sharing. Oh, and thinking it might be a problem with the iPhone USB cable I swapped that for another known good cable that one of the other guys in the office had with him. Haha... what a mystery!

Had a word with Apple (now that I've managed to write down the serial number) and the tech on the other end was being overly blasé and confident that he could fix this in a couple of minutes over the phone. I explained everything I'd tried to remedy it and he immediately put me on hold to see if he could book an appointment at a genius bar! I HAVE BROKEN APPLE!!! 😀

Looks to me like the firmware is garbled on this phone and it's become a posh paperweight. Easiest solution is probably to dig out the soldering iron and do some remedial chip replacement! 😉 Heh.

Cheers for your efforts Lawrence. Nice to feel vindicated that I'm looking in the right places at least.

You'll never believe it. You're only a complete superstar with that 11th hour suggestion! I couldn't see any crud in the bottom, but I blew really hard into the port on the offchance there was perchance some fluff in there and then gave it another try through iTunes. Managed to get it into DFU mode (first time!!!) and it only flippin' well worked. Firmware successfully restored and updated and then the software update ran, once again successfully. It's currently restoring all the data from the iTunes backup while we try to get through to a human at Apple to cancel the replacement phone they were shipping out tonight.

Massive thanks for that last afterthought! I considered I was losing my touch... being defeated by Apple gear? Me? Nooooo, never! I guess there's always a first time for everything haha.