@Gabriel.de Run YouTube for as long as you can or carry out some other screen intensive operation. This will heat the GPU/CPU and screen and may through up an issue. If it happens within 5 minutes, your hardware may be at fault. If it the issue takes a long while to manifest, it can be normal for the aging device. The battery can also affect this if it is weak or failing. The screen is usually the first part along with power button to be damaged through misuse, but is usually the last item to fail through normal use.

@Gabriel.de Not seen this issue. However if you are using a screen intensive app like YouTube, stopping the app and rebooting may help.

@smobilesoft No, 30 minutes is awy too long. It should take no more than 5 minutes. If it does not stop the process and reboot the phone to fastboot. Open a terminal in your fastboot folder and run
./fastboot reboot fastboot

If it boots into fastbootd, good. If it does not, there is an issue somewhere.

@smobilesoft If you are using the MiFlash tool, it means you are using Windows.

This is what you require to do:

1. make sure the bootloader is unlocked. You have to use the MiFlash tool to do this. Without doing this you can never down grade or upgrade your ROM to the required Android ROM or install Ubuntu Touch.
   You have to use the Rom @Vlad-Nirky mentioned - why you may ask? The person who ported UT to the device used this to ensure the vendor BLOBs (drivers) would work so everything functions and other technical reasons.

2. If you relock the bootloader it can brick your device or you may have to go through Xiaomi's ridiculous procedure to unlock it again. It means you cannot install UT or another Android ROM.

3. The fastboot method to get the required ROM onto the device is by far the easiest way. Again, I reiterate, the bootloader must be unlocked. You must boot the device to fastboot mode, then connect it to the PC. Open a terminal in the unzipped ROM folder (that @Vlad-Nirky mentioned) and being Windows, run the command ./flash_all.bat exactly as that. Then sit back and let it do it's thing, it will take some time before it reboots.

4. Once it reboots into Android, set Android up, enable Developer Options and USB debugging. Start the UT installer, attach to the PC and follow the on-screen instructions, ensuring all boxes are ticked as it is an initial install.

5. When installing UT only interact with the device when you have to. The reboot into fastbootd can take some time.

Other considerations - make sure you have drivers installed for the device (you should have). Install the latest version of Android Platform tools. Try installer version 0.10.0. Windows sometimes has an issue with fastbootd (which is not regular fastboot).

(It works well under Windows too). The ROM flash takes some time. You need to use the fast boot version, unzip the folder and then open a terminal in that folder, put the phone in fastboot mode, then run the command @Vlad-Nirky stated. Then put the device down and leave it. It takes about 10 minutes to install and will seem to hang, but leave it till it reboots. Make sure you DO NOT relock the bootloader as it can brick the device. Once it reboots, then set Android up again and you can install UT. It works well on this device.

@k.nacke It seems ok after a reboot.

@Pingu This tablet can be a nightmare to boot successfully. There are a few devices that fail to boot after upgrading through system settings and some fail using the installer. If it won't boot with an upgrade through system, then try the installer leaving wipe data unticked. If that fails, do as you have done and leave it on 20.04.

@k.nacke Readme updated and awaiting merge.

@snailc it is always best to use the ROM the porter specified, some may work, but most won't.

You have installed the correct version of Android before starting the install?

@k.nacke I will try that next time as I have acquired another one. Can I add the above to the readme on your Gitlab so any one else who is interested can follow it? (I tried but it forks, so I left it and thought I had better ask). Great work on this one. I am playing with scaling as it was scaled at 16 and I thought that was scrambling text, but even at 12 some text is missing (using the Tweak tool).

@k.nacke That worked. My 8505F is now running UT, albeit slowly, but better than Android.

Steps to reiterate (Using Windows 11 - )

1. Unlock bootloader = ./fastboot flashing unlock

Reboot into Android, set it up etc.

2. ./fastboot flash boot boot.img
3. ./fastboot --disable-verification flash vbmeta vbmeta.img

("using the vbmeta.img from the stock rom (downloaded with the Lenovo Rescue and Smart Assistant).")

4. ./fastboot flash system ubuntu.img
5. ./fastboot flash dtbo dtbo.img (don't know if this is necessary)
6. ./fastboot -w (It will error here, ignore).
7. ./fastboot reboot

Is there a recovery image yet or is the RAM size creating limitations?

@Dunbrokin OnePlus 6 and 6T won't work on Noble yet. I have tried on both, through the system update path and through the installer. It either boots into recovery or hangs at the "Your device is unlocked...blah, blah, blah" screen.

@_Joao_ Are you using windows or Linux?

@HarryBass All is not lost. If you upgraded through system and software updates, try the installer. Power the device off and using the button combination boot into fastboot mode.. Start the UT installer and attach the device, manually selecting it from the drop down box. Ensure that you leave the wipe data unticked and select what you wish to install. Try Noble (24.04.1) Stable. If it does the same thing after installing, hanging at the boot screen, redo the process and revert back to Focal (20.04) Stable.

@_Joao_ said in TB-X306F is on the installer.:

Bonjour, j'ai acheté une tablette TBX306F avec 4 Go de RAM et 64 Go de ROM, et j'aimerais savoir la procédure d'installation. Merci pour votre aide.

Translate:

Hello, I bought a TBX306F tablet with 4GB RAM and 64GB ROM, and I would like to know the installation procedure. Thank you for your help.

Hi this is an English language forum so I have translated (Google) for you....

To Install, make sure you have unlocked the bootloader and have Android 11 running on the device. Ensure developer options are enabled which you have to do to unlock the bootloader, USB debugging is enabled and then run the UT installer and follow the instructions.

@k.nacke Thats great, thats what I thought, something to try when I get time. Keep up the good work.

Is there a step missing with disabling verity and flashing a vbmeta.img?

No, still goes into a bootloop. Everything goes through correctly, no errors. Then bootloops.