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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


Contributors

Users owning this device

  • Fresh.job (Notes: trying to unlock bootloader)


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.

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 bellow. 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 mother board.
  • An old version (7.3.4.13) of Rescue and Smart Assistant (RSA), known as "Software Fix" on the product support page, can be used to flash the latest stock firmware, including recovery and boot, thus can be used to recover bricked devices, see "Product Maintenance Manual". NOTE: The Lenovo RSA only runs on Windows and requires an account.

Unbricking

The device has secure boot, attempting to flash a modified boot.img onto the device will cause it to go into a "Red State" boot loop and can not be powered off using normal methods. The device needs to be powered off for MTK SP Flash Tool to put the device in BROM mode and unbrick it.

To get out of this boot loop, keep pressing the "Volume Up" until a menu is shown, it allows you to choose between Meta mode and Fastboot mode, select Fastboot, and from there you can force the device to shutdown. You need to have a working backup of the firmware and the necessary adjacent files to flash the firmware and unbrick your device.

See also