Update of 4th August (devel)

dtarrant

@mrt10001
Thanks for the suggestion. Tablet is charging now.
Don't know anything about TWRP. What can you tell me about it?

MrT10001

@dtarrant Read this on the XDA forums.

Be aware it is for the M10 TB-X605F or L which is denoted by F/L and not for the FL which has no forward slash, so it will work on your tablet (mine is the F version (no SIM slot) of F/L) just avoid Lenovo's silly and confusing derivative naming.

You obviously need to be in fastboot mode and flash it by using :

fastboot flash recovery <path to your  TB -X605F/L TWRP>

Once in TWRP, I highly recommend wiping the cache and data partition and then rebooting to the bootloader (i.e. fastboot mode).

Then try installing UT again. If UT fails to install reinstall the stock ROM and then follow the instructions to install UT again.

(For me this has turned a mediocre Android tablet into something a lot better and more interesting, it is nice having an Ubuntu 10" tablet..)

dtarrant

@MrT10001
Thanks for the information. Mine is the Lenovo TB-X605F.
Until the fatal update, it was working superbly with UT. I absolutely loved it! A great successor to my BQ Aquaris M10 running UT.
I so hope I can coax it back to life with the help of all the community members on this forum who have chipped in with advice and suggestions.

dtarrant

@keneda
So I did a web search for low-level flash tool for Qualcomm Snapdragon 450 and it led to XDA forums. Very encouraging!
But the YouTube video demonstrating the use of the tool was no longer available.
Another forum post said that the documentation for the tool was in chinese.
I also found a long rambling post by someone in the USA which was way over my head and concluded that this approach is a non-starter for me.

dtarrant

@mrt10001
Tried charging for a long period, but still unable to boot to Lenovo splash screen. Only faint haptic buzz and blinking red led.

Keneda

@dtarrant
First see this : https://en.wikipedia.org/wiki/Qualcomm_EDL_mode

Best (safer) chance would be to use Linux tool by Andersson : https://github.com/andersson/qdl

But yes, it seems to be way harder than with mediatek chips as qualcomm did not release any official tool...

~~I also found those :~~

~~https://repairmymobile.co/flash/qfil-tool-download/~~
~~https://qfiltool.com/~~
~~https://qpsttool.com/~~

~~But none of those are official from qualcomm, and i can't say that there is no risk using those, as www is a jungle full of predators lol.~~

Edit : didn't see the first time but on the wiki, there is this link that maybe is safer than the stricked three others, and could free your brick ^^
https://www.thecustomdroid.com/qpst-flash-tool-download-usage-guide/#what-is-qpst-tool

Again, not "officialy" from qualcomm.

dtarrant

@keneda
Wow, a mine of fascinating information. I will explore. This suggests it is possible to de-brick the Lenovo TB-X605F. All you need is to know stuff and have the right tools.
Many thanks

dtarrant

@keneda
Well, whilst browsing the stuff you linked relating to QPST (Qualcomm Product Support Tool), I came across a reference to EDL (Emergency Download Mode). The bricked device has to be in EDL mode in order to use the QPST tool.
Now here's the interesting bit: If your device has been bricked accidentally and just shows a black screen and vibrates, then it's probably already in EDL mode. Wow! This exactly describes the current state of my bricked Lenovo TB-X605F.
Sounds like the QPST tool is the way to go!

Keneda

@dtarrant
I hope you sorts this brick out ^^

Luksus

@dtarrant there is also the qdl tool for flashing stock image from linux.
See install section: https://gitlab.com/ubports/porting/community-ports/android9/lenovo-tab-m10-fhd/lenovo-x605#install

Maybe it is available in your distributions repository. Otherwise you would need to build it from source.

Keneda

@luksus yes i told him about QDL also ("Linux tool by Andersson")
Thanks for the install link ^^

dtarrant

@keneda @Luksus
After re-visiting the links you sent me, I am concerned some solutions required operations no longer possible on my bricked device. So, the best option is the QPST tool. This is a Windows-based solution and I have only Linux PCs. However, my 16yr-old grandson has a Windows PC, so I showed him the instructions and he is very comfortable with them. He kindly offerred to work the magic for me whilst he is waiting for his GCSE results! Result!!! I will keep you posted.

Update: 02 Oct
Still waiting for my grandson to be available to try this approach.

dtarrant

@keneda
Still waiting for my grandson to help me try our chosen solution.
In the meantime I've been setting up my OP5t which is a great device used by Moem.

MrT10001

@dtarrant There is a Lenovo recovery tool which I have used to restore one of my tablets back to stock ROM and some Motorola phones that where apparently dead, but buzzed on power up! Running this recovery program on a Windows 11 pc, sign in with Google account, need an internet connection and it just works!

dtarrant

@mrt10001 @Keneda @Luksus @TotalSonic

Interesting, not heard of that before. Will give it a try if our currently planned solution fails. Thanks for the tip.

dtarrant

@mrt10001 @Keneda @Luksus
Here is the latest update on the situation, basically bad news.
Today, my son who is a very experienced software development engineer arrived with his windows laptop to try to fix my problem.
First he tried the official Lenovo recovery tool. He downloaded the 2GB software indicated for my device and made several attempts to connect via the usb cable. In spite of carefully following instructions, it was impossible to connect.

Next he tried the qpst tool suggested by Kenney. We assumed the tablet might still be in EDL (emergency download) mode. Again failure.

In both cases, he suspected there might have been a usb port incompatibility with his laptop (usb3 instead of usb2?).

I can't tell if the battery is charged. If I plug it into the charger, the little red led blinks, but never turns green, even after 12 hours.

No idea what to try next.

MrT10001

@dtarrant have you held the power button for about 40 seconds so the device is off. Then hold volume up and down together then press the power button till you feel it vibrate. When it does, release the power button but keep the volume up and down pressed in. If it boots up, release them. If it doesn't, you may have to split the device and disconnect the battery.

muskist

@ dtarrant
Did not read all the above. So I don't now if this can help.

After the last update I did this to make it boot:

Unplug the USB-cable so it stops charging.
Press POWER until vibration and "Lenovo" shows.
Then immediately plug in the USB-cable.

HTH

dtarrant

@dtarrant @MrT10001
Further update: Turned out my son's laptop has usb3 ports so no good. Later he resurrected an old windows laptop with usb2 ports and spent a long time updating all the software. Then, more bad news: he discovered it was a 32bit machine and the Lenovo recovery s/w requires 64bit. Now the good news: he discussed the issue with his son (my eldest grandson) who revealed he has a 64bit windows computer with usb2 ports. Furthermore, he has experience of de-bricking phones and knows about adb etc! Can't wait for him to get started!

dtarrant

@MrT10001
Just got back to my bricked tab problem and re-visited your post. You mention the possible need to split the case. Here's some information I found you may be interested in: The tablet uses a Snapdragon processor by Qualcomm. If you need to trigger EDL mode, you don't need to open the case. There's an easier way. Buy an EDL Deep Flash Cable, which has a button to trigger EDL mode. They are available on ebay quite cheaply. Best regards.