How to Unlock bootloader on Nokia 4.2

If you are the owner of the Nokia 4.2 and are looking for a method on how to unlock the bootloader then, you are at the right place. In this post, we will guide you on how to unlock bootloader on Nokia 4.2. Similar, to other smartphones, Nokia 4.2 device comes with a locked bootloader. Moreover, if you are new to rooting, then you must understand that first, you need to unlock the bootloader of the device and then install a custom recovery like TWRP to root the device. Thanks to the member of XDA, Nokia and Microsoft community Hikari Calyx, you can get your Nokia 4.2 unlocked but it requires disassembly of your device, on which we will get in more detail later in this post.

Also, rooting allows the user to go ahead and install restricted apps, mod apps, install custom OS like Lineage OS, etc on the device. Note that the unlocking of the bootloader will void the warranty of your device. So, it is better to allow the warranty period to get over and then unlock it. However, if you do not want to wait then, you can follow this guide on how to unlock bootloader on Nokia 4.2. So without any further ado, let us get straight into the article itself:

nokia 4.2

How to Unlock bootloader on Nokia 4.2

Before we begin the unlocking of the bootloader on Nokia 4.2, let us take a deep look at what is a bootloader and what advantages or disadvantages you get, once you unlock it;

What is Bootloader?

A bootloader is a program that is the first thing that boots up in your device whenever you turn ON your device. It commands the device to run the appropriate programs in order to run smoothly and provide better performance. Moreover, the bootloader is stored away from the reach of the user and is stored at a stable memory so that the user could not hamper the files. However, there are methods and ways via which you can safely unlock the bootloader of the device and go ahead with flashing a custom recovery to root your device. But, you should make sure to follow a reliable guide and follow the steps correctly in order to avoid any permanent damage to your phone.


  • You can install any custom ROM like Lineage OS, Resurrection ROM, etc.
  • You can also root your device.
  • Install a custom recovery like TWRP.


  • After unlocking the bootloader, it voids the warranty of your device.
  • You will no longer receive the official OTA updates.
  • You can brick your device if you do not follow the steps carefully.


Before we begin with the unlocking of bootloader, I would strongly recommend you to create a backup of your device storage and all your files stored on your device. Unlocking of bootloader will wipe off the entire data on your device. Moreover, it is advised to follow the steps mentioned in this post very carefully to avoid permanent damage or bricking of your device. If anything goes wrong the author or GetDroidTips are not responsible for it.


  • For this method, you need to dis-assemble your Nokia 4.2 which means, you need the back cover and upper plastic shell removed.
  • QPST (use at least 2.7.474) or any other app that could access the EDL, and Qualcomm USB port drivers are installed
  • Latest Google Platform Tools.
  • Make sure to take a complete backup of your device.
Please Note: This method is only for Nokia 4.2. It will wipe all of your device’s internal data completely. Make sure to keep a backup.

Steps To Unlock Bootloader on Nokia 4.2

  1. You can take a look at the attachment below in order to know about the location you need to use the screwdriver to dis-assemble your Nokia 4.2.
    nokia 4.2 disassemble
  2. If you are a Windows user then you need to follow the below steps:
    – Note that if the driver is already indicated as “Qualcomm HS-USB QDLoader 9008”, then you can go forward to Step 2.
    – If the driver is indicated as either “QHSUSB__BULK” (For users who have installed Windows Device Recovery Tool before) or “Qualcomm HS-USB Diagnostics 9008“, then you need to change the driver to “Qualcomm HS-USB QDLoader 9008“.
    – Once you are done with the driver change, then you need to disconnect your Nokia 4.2.
    – Now, disconnect and reconnect the battery ribbon cable, and then trigger the phone to EDL again.
  3. You need to create a partition image that has “OEM Unlocking” enabled.
  4. Just download and extract the download file from the above section.
  5. You need to use QFIL included in QPST to load the firehose file.
  6. Choose “Flat Build” and choose the “prog_emmc_firehose_8937_ddr.mbn” you extracted from the zip file.
  7. Now choose Tools>>Partition Manager, then wait for the partition list to appear.
  8. Then we have to use command below. For 64-bit Windows users, the command is:
    "C:\Program Files (x86)\Qualcomm\QPST\bin\fh_loader.exe" --port=\\.\COM8 --search_path=D:\path\to\where\you\extracted\N32_N42_unlock --sendimage=config.img --start_sector=16583680 --lun=0 --noprompt --showpercentagecomplete --zlpawarehost=1 --memoryname=emmc
    (Note: If you use 32-bit Windows, you just need to remove the “(x86)” (within space, without quotes) in the command mentioned above.
  9. Once you are done with the above procedure, you need to boot your device into Fastboot mode.
  10. To do that hold Volume Down and keep the phone connected. Close the partition manager then your phone will enter Fastboot mode and exit EDL mode.
  11. To check the unlock ability, enter the below command:
    fastboot flashing get_unlock_ability
  12. And to unlock the bootloader, enter the below command:
    fastboot flashing unlock_critical
  13. Keep pressing the Volume down key while the phone is erasing user data.
    nokia 4.2 unlock bootloader
  14. Your device will enter Fastboot mode and you need to enter the below command:
    fastboot flashing unlock
  15. Confirm the unlocking of the bootloader.
  16. That’s it!

So, there you have it from my side in this post. I hope you guys liked this post and were able to unlock the bootloader on Nokia 4.2 smartphone. Make sure that you have a complete backup of your device if things go south. Let us know in the comments below if you were able to successfully unlocked the bootloader. Until the next post…Cheers!

Source: XDA

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