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Lenovo Tab Plus (lenovo-tb351fu)

From postmarketOS Wiki
🚧 This page is a work-in-progress. Some information contained within may be inaccurate or incomplete.
In particular: Porting process still under development
Lenovo Tab Plus
A photo of the powered off tablet.
A photo of the powered off tablet.
Manufacturer Lenovo
Name Tab Plus
Codename lenovo-tb351fu
Model TB351FU
Released 2024
Type tablet
Hardware
Chipset MediaTek Helio G99 (MT8781)
CPU Octa Core (2x 2.2 GHz ARM Cortex-A76
6x 2.0 GHz ARM Cortex-A55)
GPU ARM Mali-G57 MC2
Display 2000x1200
Storage 128 GB or 256 GB
Memory 8 GB
Architecture aarch64
Software
Original software
The software and version the device was shipped with.
Android (ZUI) 14 (ZUI 16)
Extended version
The most recent supported version from the manufacturer.
Android (ZUI) 15 (ZUI 17)
postmarketOS
Mainline
Instead of a Linux kernel fork, it is possible to run (Close to) Mainline.
yes
Bootloader successfully unlocked on ZUI 17.5.10.073 (author test)

Contributors

Users owning this device

  • Fresh.job (Notes: trying to unlock bootloader)
  • Hellopratik (Notes: bootloader unlocked, recovery in progress)

How to enter flash mode

  • Shut down the device.
  • Press and hold: Volume Down, Volume Up
  • Press and hold Power until the boot logo is visible, release Power.
  • Wait until menu is visible, release all buttons.
  • Navigate using volume buttons to "Reboot to bootloader" and wait.
  • Once "fastboot mode" is visible on screen, run fastboot devices to see if fastboot sees the device.

Unlocking the bootloader

The process outlined in Unlocking Bootloaders/Lenovo ZUI doesn't work on this device.

Note Lenovo provides signed sn.img files for this device via ZUI.com, but the current bootloader [as of 20250825] does not accept the flashed data.

Working method (author verified)

A method using EDL/MTK flashing and custom XML helpers has been successfully used to unlock the bootloader on this device.

This method was developed and tested by Hellopratik on multiple devices. However, it has not yet been widely tested across different firmware versions or by the broader community.

Warning WARNING: This method involves low-level flashing and may not work on all devices or firmware versions. There is a significant risk of bricking the device. Proceed only if you understand the risks.

Installation

Use pmbootstrap to build your own installation image.

The source code provided on the Lenovo Open Source Portal needs to be cleaned up and fixed. You can try ZUI_v16.0.02.242_GKI.tar.gz instead, it can already be built using pmbootstrap, you just need some metadata.

TODO TODO:

NOTES

  • Lenovo provides a "Product Maintenance Manual" on the support page, this manual shows how to open the device and how to use the RSA mentioned below. Circuit diagram and component layout PDFs are available as download links on the last page.
  • RX and TX pins for serial debugging are clearly marked on the motherboard.
  • An old version (7.3.4.13) of Software Fix (previously known as Rescue and Smart Assistant or RSA), can be used to flash the latest stock firmware, including recovery and boot, thus can be used to recover bricked devices. NOTE: The Lenovo RSA only runs on Windows and requires an account.

Unbricking

The device has secure boot. Flashing a modified boot.img may cause it to enter a "Red State" boot loop and cannot be powered off normally.

To recover:

  • Hold Volume Up until menu appears
  • Select Fastboot
  • Shutdown from fastboot
  • Flash stock firmware using SP Flash Tool

See also