topic Re: Downgrade Z4 Tablet from .251 in XPERIA archive

Downgrade Z4 Tablet from .251

jbresee — Tue, 15 Sep 2015 19:45:36 GMT

Hi,

I accepted the upgrade to .251, and lost touchscreen responsiveness. The tablet is now incredibly frustrating to use. It misses about 1/3 of screen touches.

Sony support suggested using the PC companion to recover the device. This did a factory reset and reflash of .251, but the problem appears to be worse.

Sony support says that it is impossible to downgrade the Z4 but that's silly. Do you guys have any thoughts on how I can revert to the release prior to the .251 release?

Thanks,

Jim

Re: Downgrade Z4 Tablet from .251

Uliwooly — Tue, 15 Sep 2015 19:50:21 GMT

@jbresee

You have 2 options

either you contact your local Xperia Care

http://support.sonymobile.com/global-en/contactUs/

use flashtool

/t5/Xperia-Z2/How-to-manually-update-downgrade-root-2014-Xperias/td-p/593459

Re: Downgrade Z4 Tablet from .251

jbresee — Tue, 15 Sep 2015 20:09:48 GMT

Thanks for the reply!

I've contacted support, and they say downgrading is not possible.

I looked at flashtool, and my concern is I can't find the ROM that precedes .251. Does anyone know where I could find the previous ROM?

Thanks,

Jim

Re: Downgrade Z4 Tablet from .251

Uliwooly — Tue, 15 Sep 2015 20:11:38 GMT

@jbresee

Check the XDA forum.

Re: Downgrade Z4 Tablet from .251

_alexdon_ — Tue, 15 Sep 2015 20:49:56 GMT

@jbresee There is a huge thread about downgrading here:

/t5/Software-Updates/Downgrade-Z3-compact-and-others-from-Lollipop-to-KitKat/m-p/955640#U955640

See the solution, you can use xperifirm.

Re: Downgrade Z4 Tablet from .251

jbresee — Tue, 15 Sep 2015 21:05:23 GMT

Thanks!

That's what I needed.

Re: Downgrade Z4 Tablet from .251

_alexdon_ — Tue, 15 Sep 2015 21:05:56 GMT

Keep us updated.

Re: Downgrade Z4 Tablet from .251

LiveWire07 — Wed, 16 Sep 2015 02:20:00 GMT

So I am thinking of trying this myself - however, I have never downgraded or rooted my product before.

My question is, if it is rooted (or in this case downgraded) will I be able to upgrade in the future on Sony's official released software/updates? Or will my device stay rooted?

Re: Downgrade Z4 Tablet from .251

_alexdon_ — Wed, 16 Sep 2015 07:41:29 GMT

Downgrade is not equal to root. With downgrade you simply put an older firmware version. Warranty should also be intact. Updates will be received normally.

Re: Downgrade Z4 Tablet from .251

LiveWire07 — Fri, 25 Sep 2015 14:58:30 GMT

I wanted to thank this team for the recommendation to downgrade - it solved my problem. As I assumed, the issue was with the .251 update.

I wanted to rollback to my stock version of the system software, but I was unaware of which version that was. Since I live in the U.S. my tablet was imported and I believe it came from Asia (specifically I want to say Hong Kong based on the service locations in the instruction manual).

Alas, Xperifirm did not have the older version of the software from the Hong Kong server, so I had to roll back using a version from Central Europe. Based on the region difference, I assume this will not cause an issue for the tablet?

Re: Downgrade Z4 Tablet from .251

kristofior2015 — Thu, 22 Oct 2015 14:36:08 GMT

A little feedback on this 251 downgrade topic :

On my side I had the following touchscreen issues :

Problem around bottom left corner with left thumb.

First I thought it was because of the PRT13 sony screencover.

I have downgraded but finally the issue was still there.

It seemed to me that removing the cover was reducing the touch issues but did not solve them at all.

Checked it was not a software issue putting the tablet upside down (new bottom left was physical top righ) and no more problem with my left thumb on bottom left corner.

Problem was enhanced using the cover SCR32, in this position, the back of the tablet was not on a 'back pushing surface' (table or my fingers), and the problem was so horrible, touch issues more and more.

I thought my finger had problems (maybe a surgery would solve it ? ha ha), but not issues at all with an iPad or Samsung with screen covers...

So looked like really a hardware issue.

Downgrading or upgrading did not solve it (I had the same issues with downgraded version).

Finally I have returned the Z4 to the reseller, now waiting for a fresh new one....

Wait & See...

Cheers.