@stevetheobscure Tips:
Follow this and be patient, very patient...

First off, run it through the installer and install Xenial or Focal. If it boots into the OS, great, don't power off and leave it charged.

If it hangs though, at the Lenovo splash screen, this is the patient part....Follow these steps....

1. Power off.
2. Boot to recovery
3. In recovery Format data and cache, Mount the system and reboot to recovery.
4. In recovery now mount the system and reboot to recovery - do this at least eight times on the final time reboot to the bootloader.
5. Connect to the PC and with command prompt open run fastboot continue, leave it for 20 seconds, if no boot, power off and boot to fastboot and repeat this step four times.
6. Still no boot after step 5, boot to fastboot and run the command fastboot reboot. Do this at least four times, but by now, it should boot.
7. if the above steps fail, leave it for an hour and repeat.

It took a while for me to work this out, but it has worked every time on these tablets, I was just very patient.

@hunter_tor To get the 3T working with UT, it is Xenial only (16.04), you have to ensure the data partition is EXT4. Use the installer version 0.10.0. Download this version of TWRP and boot it from fastboot - use the command: fastboot boot (location of your TWRP file)

Once in TWRP format date to EXT4, then wipe SYSTEM, CACHE and the others . Reboot to the bootloader and do the same again, but it is not necessary to wipe the system etc, just format the DATA again to EXT4.

Reboot to the bootloader and fire up the UT installer and connect the device and manually select it from the drop down box.

Leave the "wipe data" box unticked and follow the instructions on the installer. Let it do it's thing. Once it is at the screen in your image, leave the device, it can take up to 15 minutes to install.

The OP3 and 3T are very similar, TWRP for 3 and 3T is the same.

Ensure you are on OxygenOS (9.0.6) before starting the UT install.

The two main points of a failed install I have found for the device is using the latest UT installer, use 0.10.0 instead and the incorrect formatting of the data partition to EXT4.

Also as @moem pointed out, the OP3T is old and Xenial is now unsupported... (It still works though).

@stevetheobscure The TB-X605F and X is functional on 16.04. On 20.04 there are things not working, mainly the cameras. On 24.04 it is not working (yet?).

This tablet can be a nightmare to boot, but with patience I have got there on all of mine. For some reason, some will boot and reboot absolutely fine. Others will just hang at the Lenovo splash screen and take some techniques to get booting, that are not software tweaks..

@egregiousecan won't boot at all? Can you boot to the bootloader (fastboot)?

@Persinto The specs for the device are old. 2Gb of RAM these days won't give you the best experience and the dated kernel would require a lot of work to bring it up to spec. Even Android runs poorly on 2Gb of RAM from Android 9/10 forward. I am not saying to not have a go at porting to the device, but it will be a hard road.

@danfro Many moons ago I spoke to the porter. He was hoping someone would pick up the port as he couldn't get the sound to work properly and unfortunately it then went the way of the Nexus 4, 5 and others.

@computersalat You miss the point, there was a port for it, but it was not complete, i.e. no sound and the porter couldn't resolve it for their reasons. I have a few devices that have UT ported to them but the port has failed, usually no sound (a bit of a necessity with a communications device), no modem, wifi and so on. Porting devices fail for many reasons, one of the main reasons is proprietary drivers (that require reverse engineering) and kernel issues which can take a lot of dedication to sort out...

@computersalat No, as @vlad-nirky pointed out. There is a port for Xenial (16.04), but there is no sound and has not been worked on for a long time. If you want a more up to date version of Android, check out /e/OS.

@E-Z-Tux said:

The Lenovo fix tool needs the tablet to be turned on

The Software tool requires the tablet to be switched off when recovering using serial number.

@jrgood78 I have had this on other devices after an INCELL screen replacement, more recently a OP 6T. The screen works in Android but not on UT. You could try going back to Android, making sure everything works, then reinstalling UT and see if the screen is picked up.

BTW, INCELL is a type of screen that is cheaper and more hard wearing than more expensive OLED screens. They are not as vibrant colour wise than OLED screens and if the fingerprint reader is under the screen, that usually won't work with n INCELL screen replacement.

@KJU Just to point out, Ubuntu Touch is the name of the mobile operating system that you have installed and given good account.

UBPorts is the charitable foundation that helps develop and finance Ubuntu Touch through donations and sponsorship.

@ResuWen Check the end of this thread on XDA-Developers forum. There is a media fire link that works.

@E-Z-Tux You don't need to power up the device. You log in to the software fix tool with a Lenovo account or a Google account. Select Tablets. Select use the serial number to recover. Enter the serial number of the device. Download the ROM. Ensure the tablet is powered off. Follow the onscreen instructions to recover the device, which involves holding volume up and volume down and plugging in the USB cable plugged into the PC when told to do so. Then leave the device alone till it reboots.

@E-Z-Tux You don't need to have USB debugging enabled. If you have the serial number of the device (sticker on back of tablet or on box) you can recover to Android.

@MadDino it elevates the command. I have had to use it installing UT on other devices.

@MadDino Put the unzipped folder on your desktop. Attach the phone to the PC in fastboot mode. Open a terminal in the unlock folder. Run the command ./unlock.cmd. Note the ./ in front of the command.

@E-Z-Tux All is not lost. You need to charge the device up. Put it on charge for a day. If it fails to boot after that then you can use the Lenovo Software Fix Tool to recover Android to the device (requires a Windows PC).

@MadDino I have used Windows 11 to unlock the bootloader and install UT my ASUS devices. It is not the easiest phone to install UT onto. The build number won't make a difference unlocking the bootloader, but when you unlock the bootloader use this (quote from devices page):

"The port is based on Android 9 firmware (WW-16.2017.2004.063) and Lineage 16 vendor image. Current Recovery will be replaced with Ubports Recovery!"

I think you are experiencing difficulties with the ASUS drivers. On Windows uninstall the drivers, reboot the PC, install the drivers and try again. If that fails try disabling driver signing which is a bit of a messy workaround. I found that one of the Windows updates messed with the drivers and uninstalling them and reinstalling solved it.

@MadDino The build number should not make a difference. Try running it in an administrative command prompt and run the command with ./ In front.

@MadDino Start the device up and the bootloader should be unlocked.