AT&T Galaxy S5 Lollipop update was launched back in early April but you didn’t have the full firmware available for download and manual installation — until today! Using the firmware — baked into Odin already — you can update your KitKat running AT&T Galaxy S5 to Android 5.0 Lollipop upgrade in just one click. Lollipop update build no. is G900AUCU3BOC4, in case you were wondering. OC4 update in short!

If you had rooted your Galaxy S5, and changed the stock recovery, you couldn’t accept OTA anymore, thus may be left with KitKat. Yes, you cna still make your way to Samsung Lollipop with stock based custom ROMs, but it’s really frustrating to not being able to install back stock firmware on your own, because, many a times, you need just that. Well, not anymore, just look below, it’s the Odin firmware you’ve been craving so badly. Credit for the one click Odin firmware package goes to numatron, thanks!

AT&T Galaxy S5 Android 5.0 Lollipop Update G900AUCU3BOC4

Downloads

The above firmware already has Odin baked right into it, so you won’t need Odin separately.

Supported devices

  • AT&T SAMSUNG GALAXY S5 (model no. SM-G900A)
  • Don’t try this on any other Galaxy S5 variant from Samsung!
  • Don’t try on any other device whatsoever!

Instructions

Disclamer: Installing an official firmware through Odin doesn’t void your device’s warranty, but it remains an unofficial process and thus you need to be cautious of it. In any case, you only are responsible for your device. We won’t be liable if any damage occurs to your device and/or its components.

Backup important files stored on your device before proceeding with the steps below, so that in case something goes wrong you’ll have backup of all your important files. Sometimes, Odin installation may delete everything on your device!

  1. Disconnect the Galaxy S5 from PC if it’s connected. Then install Galaxy S5 drivers (method 1 there!) first of all. Double click the .exe file of drivers to begin installation. (Not required if you have already done this.)
  2. Download the firmware file from above.
  3. Boot AT&T Galaxy S5 into download mode:
    1. Power off your S5. Wait 6-7 seconds after screen goes off.
    2. Press and hold the three buttons Volume Down + Power + Home together until you see warning screen.
    3. Press Volume Up to continue to download mode.
  4. Extract the firmware file (Copy of G900AUCU3BOC4_OneClick.zip). You can use a free software like 7-zip for this. Install 7-zip, then right click on firmware file and under 7-zip, select ‘Extract here’. You should get this file, G900AUCU3BOC4_OneClick.exe upon extraction.
  5. Run the firmware file. For this, double click on extracted file, G900AUCU3BOC4_OneClick.exe which will actually take long time to open an Odin window as you see below.
    AT&T Galaxy S5 Lollipop Update Odin TAR
  6. Connect your Galaxy S5 to PC now using USB cable. Odin should recognize your S5. It’s a must. When it recognizes, you will see Added!! message appearing in the Log box in bottom left, and the first box under ID:COM will also show a no. and turn its background blue. Look at the pic below.
    • You cannot proceed until Odin recognizes your device and you get the Added!! message.
    • If it doesn’t, you need to install/re-install drivers again, and use the original cable that came with device. Mostly, drivers are the problem.
    • You can try different USB ports on your PC too, btw.
      AT&T Galaxy S5 Android 5.0 Update Odin
  7. Click the Start button on Odin now to begin flashing the firmware on your AT&T Samsung Galaxy S5. Wait till installation is finished, after which your S5 will reboot automatically. You’ll get PASS message as show below upon successful installation from Odin.
    • If Odin gets stuck at setup connection, then you need to do steps 6 to 12 again. For this, close Odin, disconnect your device, remove battery, insert it back after 5-6 seconds and then start from step 6 again.
    • Or, if you get FAIL in the top left box, you need to try flashing again, as stated just above.
  8. First start of the device may take time, so wait patiently again. Check the Settings > About phone to confirm new firmware.

That’s it. Enjoy the G900AUCU3BOC4 Android 5.0 firmware, OC4 in short, on your AT&T Galaxy S5!

If you need any help with this, let us know via comments below and we will try our best to help you out.