For anyone who repeatedly flash many custom ROMs every single day, then you should know how to unroot and return your Sprint HTC One M8 back to stock with the RUU or stock firmware. Because we never know when we will get the problem, so when your smartphone gets a trouble or you accidentally bricked it, you won’t be panic as you already know how to handle it, some people even return theirs Sprint HTC One M8 to stock for warranty purpose.
Actually, without a stock firmware or RUU we can still restore our Sprint HTC One M8 back to stock, by using a nandroid backup that has been created in the past by using a custom recovery like CWM or TWRP. Sadly, not every person is careful about this, and a lot of them have no a stock Nandroid backup saved on their phones. They were too excited to remember to perform a backup.
- The most recent version of HTC USB drivers for Windows, get rid of the HTC Sync from your computer.
- Working adb and fastboot files on your PC.
- An S-OFF’ed Sprint HTC One M8, because some RUU requires you to have SuperCID which can only be achieved if your M8 has S-OFF.
- Grab the stock RUU or firmware for Sprint M8. Currently, the RUU available in flashable zip and executable exe, but the OTA firmware only available in and fastboot-flashabe zip.
- Enable USB debugging on Developer options.
Easily unroot and restore Sprint HTC One M8 back to stock with RUU – Windows executable file (*.exe)
We assume here that your M8 was gained S-OFF with Firewater.
- Grab the executable RUU file (Sprint_HTC_One_M8_Harman_1. 54.654.9_RUU. zip), extract it and you will find an executable file there (ARUWizard.exe).
- Connect your phone to the Windows computer, and make sure it recognized.
- Previously we had to set our device’s CID to “11111111” (SuperCID). We need to boot into bootloder, open adb and fastboot folder, then Open a command window from there. Now run the command below:
adb reboot bootloader
Once boot into fastboot mode, run SuperCID command below:fastboot oem writecid 11111111
- Next, go to your PC and run the executable RUU (ARUWizard.exe), a ROM Update Utility window will appear, then follow any commands you see.
If you’re not happy with the executable RUU that has been described previously. Alternatively, you can use the flashable RUU or stock firmware, but we have to flash it manually via fastboot command
- Move the RUU or firmware file into the fastboot folder.
- From fastboot folder Open the Windows command prompt (CMD).
- Connect the Sprint HTC One M8 to the computer.
- Firstly, we need to boot into bootloader mode:
adb reboot bootloader
Your phone will be turned off and then boot directly into bootloader mode.
- Test fastboot functionality, should show your device serial number when identified:
- Boot into HTC RUU mode:fastboot oem rebootRUU
Once entering into RUU mode, you can see an HTC logo with progress bar down below.
- Now flash the RUU (zip) or stock firmware file that you downloaded before.fastboot flash zip RUU_File_Name.zip
- Flashing process will run, do not forget to pay attention to the CMD window, when finished you have to manually reboot it, run the following command:fastboot rebootFlashing RUU via SD card
Another Method to flash RUU or stock Sprint HTC One M8 firmware without a computer
Reset UNLOCKED banner to LOCKED and return to S-ON
- Take out your current external SD card.
- Reformat the SD card to FAT32.
- Rename the RUU (zip) or stock firmware to “0P6BIMG.zip”.
- Move the “0P6BIMG.zip” into the root directory of the ext SD card.
- Shut off your phone, re-insert the SD card.
- Reboot into bootloader mode (press and hold Vol down + Power).
- Once RUU is discovered by your phone, follow any prompts you’ll see on your phone screen.
Source:xdaFilled Under:Unroot and RelockRelated Mods
- Soon after the S-OFF is obtained, the LOCKED banner on bootloader will be altered to UNLOCKED. You can make reset it again by following a guide here.
- Return to S-ON from S-OFF is seriously not recommended, most people will not undertake it. Since there is a chance you will not be able to get an S-OFF again at some point.
- Boot into HTC RUU mode: