Problems with iphone 4s and ios 9.3.1

Identical situation here: error 29 during "updating firmware". In my case it turned out iOS 9.3.1 no longer liked the 3rd party replacement battery I installed two weeks earlier. I put in the (dying) original battery and the update worked.

iPhone 4S update to iOS 9.3.1 saga

The following happened while iTunes was attempting to update iOS to version 9.3.1 on 4 April 2016, which apparently just “Fixes an issue that causes apps to be unresponsive after tapping on links in Safari and other apps”.

Symbol displayed on iPhone screen: the white charger cable with an arrow pointing to an iTunes icon. A small window appeared, saying "The iPhone "Walter's iPhone could not be updated. An unknown error occurred (4005)."

When I clicked on the More Information button on the error message it directed me to the following web page:

https://support.apple.com/en-gb/HT201444

When I clicked on OK on the small error message window, another small window appeared, saying: "There is a problem with the iPhone "iPhone" that requires it to be updated or restored. The problem may be fixed by updating your iPhone, which preserves your settings and content. However, if updating doesn't work, it may be necessary to click Restore, which erases all settings and content. If you backed up this iPhone to this computer or iCloud, you'll be prompted to restore the backup onto the iPhone."

[Buttons:] Cancel, Update, Restore

I clicked the Update button and another small window appeared, saying: "If your iPhone can't be updated, you will need to restore it to its factory settings. iTunes will update your phone to iOS 9.3.1 and will verify the update with Apple."

[Buttons:] Update, Cancel

I clicked the Update button and iTunes said it was "Extracting software..." then another small window appeared, saying: "The iPhone "iPhone could not be updated. An unknown error occurred (11)."

[Buttons:] OK, More Information

I clicked on the More Information button and was taken to the following web page, titled "Resolve iOS update and restore errors in iTunes:

https://support.apple.com/en-gb/HT201210

I then updated to the latest version of iTunes (12.3.3) on my computer and also selected to install "Apple Software Update" version 2.2. I was then prompted to restart the computer, which I did. After it restarted, iTunes opened automatically and showed me the same message window as before:

"There is a problem with the iPhone "iPhone" that requires it to be updated or restored. The problem may be fixed by updating your iPhone, which preserves your settings and content. However, if updating doesn't work, it may be necessary to click Restore, which erases all settings and content. If you backed up this iPhone to this computer or iCloud, you'll be prompted to restore the backup onto the iPhone."

[Buttons:] Cancel, Update, Restore

I clicked on the Update button and it then showed me the same warning message as before:

"If your iPhone can't be updated, you will need to restore it to its factory settings. iTunes will update your phone to iOS 9.3.1 and will verify the update with Apple."

[Buttons:] Update, Cancel

I clicked on the Update button and iTunes extracted the software then eventually said something like "Preparing iPhone for software", then "Waiting for iPhone". There was also a pop-up message from Windows saying "Installing device driver software" or something very similar.

Then iTunes said:

"iPhone Recovery Mode

iTunes is updating the software on this iPhone." with a status of "Waiting for iPhone..."

A few seconds later, the symbols displayed on iPhone screen changed from a white line showing the update process to the white charger cable with an arrow pointing to an iTunes icon. Then an error message window appeared in iTunes, saying: "The iPhone "iPhone" could not be updated. An unknown error occurred (4013)."

[Buttons:] OK, More Information.

I clicked on the More Information button and was directed to the following web page which suggested installing the latest version of iTunes (already done), checking for updates to my PC (already done), try to restore your device using another USB cable, try to restore your device on another computer, Force your device to restart:

https://support.apple.com/en-gb/HT201444

I shut down the PC and plugged the iPhone in using a different cable and a different USB port. Then I started the PC and Windows told me it was installing and configuring updates! Upon the completion of start up, iTunes opened automatically, displaying the same message as previously:

"There is a problem with the iPhone "iPhone" that requires it to be updated or restored. The problem may be fixed by updating your iPhone, which preserves your settings and content. However, if updating doesn't work, it may be necessary to click Restore, which erases all settings and content. If you backed up this iPhone to this computer or iCloud, you'll be prompted to restore the backup onto the iPhone."

[Buttons:] Cancel, Update, Restore

I clicked on the Update button and it then showed me the same warning message as before:

"If your iPhone can't be updated, you will need to restore it to its factory settings. iTunes will update your phone to iOS 9.3.1 and will verify the update with Apple."

[Buttons:] Update, Cancel

While iTunes was "Preparing iPhone for software update..." another error window appeared: "The iPhone "iPhone" could not be updated. An unknown error occurred (-18)."

[Buttons:] OK, More Information

I clicked on the More Information button and was directed to the following web page:

https://support.apple.com/en-gb/HT201210

Then I clicked on the OK button on the error message window. I tried to close iTunes but it told me "iTunes is updating the software on the iPhone "iPhone". If you quit now, you will need to restore your iPhone..." then the message disappeared before I could finish typing this and the symbol on the iPhone changed to the Apple icon with a grey/white line underneath it and iTunes said "Waiting for iPhone..."

I went away to have a cup of coffee for 5 minutes and when I came back there was yet another error message from iTunes: "iTunes could not connect to the iPhone "Walter's iPhone" [at least it knows my nickname again now] because an invalid response was received from the device."

[Button:] OK

I clicked on the OK button and iTunes returned to displaying a list of my music. When I clicked on the iPhone's Home button the screen displayed: "slide to upgrade", so I slid to upgrade, entered my passcode and a black apple logo was displayed against a white background (previously it was a white logo on a black background) with a grey progress line underneath it that was slowly but steadily being filled with a darker grey colour, presumably (hopefully) indicating that something was happening. After a couple of minutes the line was filled completely and it disappeared so that only the black Apple logo was displayed. Then the phone's display announced "Hello > slide to set up".

I slid to set up, entered my passcode and the phone's display announced "Update Completed". And lo and behold, it was.

I suppose that will teach me not to upgrade my version of iOS so readily in future. I am officially unimpressed.

@spotlight28, @Christian Leue: Thanks for pointing this out. I also have a 4S equipped with a replacement battery, currently running on 9.2.1. Now I would be interested to know, if this "error 29" -thing came out new with the 9.3 series, or if it was implemented in earlier versions of iOS already. Did you guys experience any problems updating to 9.2 or earlier as well? I know that my phone survived updating to 9.2.1 *with* the replacement battery but wonder if that will also be true for 9.3…

Hi,

To all who are experiencing the Error 29 issue, I confirm that returning the battery to the original resolves the issue...

Now this pointed out a funny thing to me... I had iPhone having it's battery replaced at an Apple Support center... would assume they would use original batteries... apparently not 😟

To recover it, swapped the battery with another 4S that was stopped but had original battery on it, and the update ran correctly...

Feels like asking... Dear Apple team, are you using "fake" original Apple batteries in (at least some of) your Support Centers?!

For anyone interested: Monday's iOS 9.3.2 requires the original battery in the 4s too. But no worries, my turn-around time for the battery swap is down to 3 minutes by now.