Installation issue with UBports-installer with Z4-Tab

z4Tab

@Guf
Many thanks for your response. However, I am amazed that you have never tested these preparation steps yourself. Your suggestions with TWRP are also new territory for me. Now I have seen in the new version of the UBports-installer (0.8.5-beta) that there are no more preconditions. So I tried to install ubuntu touch on my Xperia z4 tablet. Unfortunately the installation got stuck and the tablet can no longer boot successfully. There is an endless loop with following Error messages for a few milliseconds:

E:failed to mount/cache (Ivalid argument)
E:Can't mount /cache/recovery/last_locale

Now I wanted so badly to use Ubuntu instead of the Android "spy system", but now the tablet is just junk.

Is there someone who can help me so that I don't have to throw the tablet away?

Keneda

@z4tab
I don't have Z4, so can't help you with this, but ubports installer, and uTouch, do not brick devices.
So your Z4 is not junk.

z4Tab

@keneda

May be that junk is not the very right word for my tablet. In spite of this the tablet has become useless for me! Unless someone knows a way for that.

Keneda

@z4tab
I'm sure you'll get help, be patient, and, if no answer, up thread from time to time, not more than once a day.

AntiDroid

I do not know the answer but it would be the same if you had tried to flash android and failed. With that said I am sure there are instructions on XDA forums on how to unbrick this device. After that it would be Android again and you could try Ubuntu Touch again or leave it Android if you are not comfortable flashing devices.

Lakotaubp

Not having this device I can only go with what @AntiDroid said that there will be a way of reinstalling android if you wanted then retry the installer. You may also be able to install TWRP for your device then run the installer. One last thing I see the installer only lists the 771 not 712. Knowing how specific the installer is and not knowing anything about these tablets I would double check that is not an issue if yours is a 712.

z4Tab

@lakotaubp Unfortunately, the problem is an endless loop. I do not get into the recover mode or something else. So I don't know how to reinstall Android. Likewise, I can't install TWRP or something like that.

Does anyone here have any ideas how to revive the device?

I can only get out of the loop using PWR + Volume-up. Then the tablet is switched off. After switching on, I keep getting into the loop. By pressing PWR + Volume-up or PWR + Volume-dwn, I get stuck in the white Sony-Bootscreen. Switching off is only possible with PWR + Volume-up.

Guf

@z4tab Sorry for the issues, but if you really want to test it, please, could you use the guide: https://forums.ubports.com/topic/4351/porting-ubuntu-touch-ubports-to-karin-sony-xperia-z4-tablet-sgp771-and-karin_windy-sony-xperia-z4-tablet-sgp712?_=1630513955780

z4Tab

@guf please read my statement carefully it is an endless loop in which the device is stuck. So I can no longer install anything, etc.
I am afraid my tablet is only scrap metal now!

Mario.CH

@z4tab
Hi,
Did you only turn off the tablet with your method or did you also reset it, for example with the following Procdedur.
Try a total reboot by pressing and holding the power button until the device vibrates 3 times in quick succession.
The device should always have enough 'juice' in the battery.

nero355

@mario-ch said in Installation issue with UBports-installer with Z4-Tab:

@z4tab
Hi,
Did you only turn off the tablet with your method or did you also reset it, for example with the following Procdedur.
Try a total reboot by pressing and holding the power button until the device vibrates 3 times in quick succession.
The device should always have enough 'juice' in the battery.

Considering the fact that the device has a old Qualcomm SoC according to it's devices page : https://devices.ubuntu-touch.io/device/karin/
It got me thinking of the same thing : Try all the tricks that go with that generation of SoC's

Pressing the Power button for a long time and waiting for EDL Mode to be entered.
In the worst case you can use a spare USB Cable and then shorten the right wires together to get to EDL Mode : https://www.getdroidtips.com/5-methods-to-enter-edl-mode-on-any-xiaomi-smartphones-qualcomm/
Also see : https://duckduckgo.com/?t=ffab&q=qualcomm+edl+mode&iax=images&ia=images
For pictures of the cables you can buy so you don't have to build them yourself!

TL;DR : Bootloops are OK! That means you can safe your device!

z4Tab

@Mario-CH:
The only way to turn off is press "PWR"+"Vol-". Then the tab vibrates 3 times and is really off. But only pressing "PWR", also for a long time - nothing is happen!

@nero355:
EDL-mode sounds good. May be this is the only way to activate the tablet again. But I can't find any way to set the tablet in EDL-mode. Also with edl-cable (short D+ with GND) is not working!