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Nokia Lumia 620 (nokia-rm846)

Nokia Lumia 620
The Nokia Lumia 620 powered off.
The Nokia Lumia 620 powered off.
Manufacturer Nokia
Name Lumia 620
Codename nokia-rm846
Released 2013
Original software Windows Phone 8
Chipset Qualcomm MSM8227
CPU Qualcomm SNapdragon S4 Plus Dual Core 1.0 GHz
GPU Adreno 305
Display 480x800 LCD_TFT
Storage 8GB
Memory 512MB
Architecture armv7
Non-Android based device
USB Networking
3D Acceleration
Mobile data




Users owning this device

Button Shortcuts

  • Hold Power + Volume down to force the phone to reboot
  • Hold Volume down and connect it to the PC to boot it into fastboot mode
  • Hold Volume Up and connect it to the PC to boot into the recovery system

Installation of Android

For now, it is necessary to first install Android on the device to use fastboot as flash tool.


You will need some tools for Installation:

Backup Data

Postmarketos is not ready to use as a daily driver yet. So use a phone you do not need for the development. If you have some data on it, back it up now.

Clean Firmware Install

Use the Windows Device Recovery Tool to install clean Firmware. This is to avoid errors and to gain the FFU-image.

Check you Storage

Open WPInternals with your phone connected to your Windows PC. Reboot it into flash mode, to get more information. There it says, from which manufacturer your storage is. If it is from Samsung, it can cause a brick of your phone. If not, you are good to go.

Unlock the bootloader

Now use WPInternals to unlock your bootloader. You will need an FFU-image for that. Use the Download page of WPInternals to download it.

Afterward, you need the Emergency Loaders. You can also download the needed files with the Download page.

Then you need the Engineering SBL3 files, which can be found here Now unlock the bootloader.

Connect your phone in mass storage mode

Use WindowsPhoneInternals to switch to the mass storage mode. It could be that you have to give the device a drive letter.

Backup your phone

Use the WindiskImager to Backup your phone (the MainOS Partition). Therefore select the Device, select a folder for your Backup and give it a name. Afterward, switch to Normal Mode again by holding down the volume down and power key together for 10 seconds.

Flash the LittleKernel Bootloader

To boot to Android you need to flash the LittleKernel of Android4Lumia. Therefore use the iflash tool.

Install the CustomROM

At the end of the process the device boots into the TWRP-recovery. Wipe all partitions to avoid errors. Afterward install the LineagesOS with ADB-Sideload. In TWRP got to Home > Advanced > sideload. Then use:

$ adb sideload <>

Replace < with a path to the downloaded LineageOS-file.


If your device stays black but is connected as QSUSB_DLOAD, use the WindowsDeviceRecoveryTool to make a clean firmware install.

See also