How can i fix my iphone 5s update fail ios 12.5.3

Hi, try connecting it to your i tunes and then download the software from there while your phone is connected. This should take about 30m. Restore the phone from there.

Try this:

Update your device using your computer

If you can’t update wirelessly on your device, you can update manually using a computer that you trust. If your computer is using Personal Hotspot on the device that you’re updating, connect your computer to a different Wi-Fi or Ethernet network before you update.

1. On a Mac with macOS Catalina 10.15, open Finder. On a Mac with macOS Mojave 10.14 or earlier, or on a PC, open iTunes.
2. Connect your device to your computer.
3. Locate your device on your computer.
4. Click General or Settings, then click Check for Update. 
5. 
6. 
   
7. Click Download and Update.
8. If asked, enter your passcode. If you don't know your passcode, learn what to do.

If you see error messages on your computer or need more space to update

Get help if you see error messages while updating your device with your computer. Or if you need more space for an update, you can delete content from your device manually.

* Upgrading to the latest version of iOS or iPadOS software provides the latest features, security updates, and bug fixes. Not all features are available on all devices or in all regions. Battery and system performance may be influenced by many factors including network conditions and individual use; actual results may vary.

Hope this helps

I have the same issue. My iPhone 5s is now essentially bricked and unusable.

Tried to update to ios 12.5.3 - failed everytime

Then used itunes. This worked, but the phone was unable to proceed after restart, same issue - No Service.

I then did a backup in order to restore.

After restore, I follow the setup and land up on a screen:

Unable to Activate

An Update is required to activate your iphone

Lean more at apple.com/uk/support

iTunes -> Iphone screen is stuck, completely blank

I have already reset, removed the sim, etc

I NEED ASSISTANCE TO SORT THIS OUT

Welcome, Risa2020, to Apple Support Communities!

Your screenshot shows that your iPhone is in Airplane mode, so it can no longer connect to the Internet.

That would seem to be the reason for the error you are seeing.

You can, of course, also solve the issue using khajotia‘s suggestions.

HI Risa, you have a valid point! I didn't notice that the flight mode was on. :)

Same problem here as taarik7

Need help!