How To Re lock Boot Loader On Xperia Arc [Step by Step Guide]

After unlocking boot loaders peoples are getting some errors when we accept FOTA updates (one of my friends get bricked xperia play after updating it). after re-locking boot loader you will be able to use SEUS again and repair your phone’s firmware .

What is solution ?

who already unlocked their boot loader and want to relock it again ,now this is possible and all credit goes to XDA member ‘Blagus’ . he created a 98KB’s small file that needs to flashed with “flashtool” and you will get your boot loader locked again.

What I need to re lock Xperia Arc ‘s bootloader ?

  1. PC Companion and Update Service installed on your PC
  2. FlashTool_0.2.9.1.exe – Download link
  3. Xperia Relock bootloader.ftf – Download link

Step by Step Guide to relock Sony Arc bootloader

  1. Run FlashTool_0.2.9.1.exe
  2. Now you will see there are some folder automatically extracted ,we need to “firmwares” folder
  3. Copy “Xperia Relock bootloader.ftf” file to “firmwares” folder
  4. run “X10FlashTool.exe” by double clicking on it
  5. Once the program opens — click on the “Flash” button.
  6. See image below , you will see like this


  7. Now it should ask you to connect your phone to the PC.
    plug the USB cable to PC, connect usb cable to phone while holding the “Back” key (key at the bottom left on your Arc),
  8. Once the phone gets connected — Flashtool will automatically start the flashing process.
  9. And once the process gets finished, disconnect your phone from PC and switch it ON.

Video Guide by TheAndroidSoul



All thanks to XDA member Blagus for making it possible ,go to this thread on XDA to thank him. and also hit big thanks to ‘s Shivam for Video Guide.


In future if you need to unlock bootloader again you can follow this easy step by step guide on how to unlock xperia play,arc,neo and pro bootloader . in this guide I unlocked bootloader of xperia play , you can unlock Arc,neo and pro as well.

Before unlocking check which phones are fulfill requirements of unlocking bootloaders

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About kày

Kuldeep Singh is founder of androidflip , young blogger from india who loves to write about android and technology. Follow him on twitter @androidflip


  1. Raybarlis says:

    Hi there, I tried unlocking the boot loader and then suddenly I update software after that my phone wont start anymore can you help me please

  2. Anonymous says:

    my mobile is Xperia play with unlocking the boot loader ( i bought it like that ) and i update it to 2.3.3.
    How can i root it if my firmware 3.0.1.A.0.145 (UK), I have Macbook Pro with W7
    If there is any way to re-lock the boot loader

  3. Fernandoksp says:

    Hey, its impossible to unlock again…is that right?

  4. Hey, after I unlocked the bootloader, all my previously downloaded apps are gone. How do i get them back?

  5. LemonCrazy says:

    Does this work for Xperia PLAY also?

  6. i have resolt!!!
    thanks i love you!!!
    to italy …..nik

  7. Hier nach kann ich immer noch nicht rooten. ???

  8. Kuldeep, do you have the TFT full file for the Xperia Neo ? I unlocked my phone and flashed the boot.img… so I can’t lock before I restore the bootloader and reinstall the /system folder to original, cause the rom doesn’t have the MTS option, then, I can’t update the Android with the PC Companion… and more dificult yet my Neo version is the MT15a (MT15i TFT just does not flash), can you help me to solve this problem?

    Thanks in advance.

  9. Glauco Goncalves says:

    Thanks a lot all guys whom work for everithing’s worldwide pleasure!!!

  10. Hi there,
    First of all, i would like to thank the “Creator/Publisher” of this Blog/Thread..

    I have Sony Ericsson Xperia arc (LT15i)..

    Two days ago, i Rooted/Unlocked boot loader, installed custom rom (Cyanogen Mod 9.1).. Rooted perfectly, used mod 9.1, got bored..

    Now again, i wanted to go back to my Original Stock Firmware (4.0.4), so lots of search on net (after wasting lot of hours) i arrived here..

    I followed your step-by-step guide, and Rooted/Locked boot loader back to original status (Stock)..

    Thank you million times,
    Thanks to the XDA Team..

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