Can I downgrade Xperia tablet Z2 Castor from LOS 18.1 to /e/ q?

I installed LOS 18.1 on my Z2 to play around and see how LOS is feeling on the tablet, without thinking, that it might be a problem to downgrade it to e-1.6-q???

Will there be a/e/ upgrade to R soon - Linage 18.1 is running smoothly? or is it no problem to downgrade?

because 1 day trial with linage is enough!

Regain your privacy! Adopt /e/ the unGoogled mobile OS and online servicesphone

Hi @kultex,

I think this warning depend more on what was the stock Sony android level.
If it was lower or egual to android 10, don’t care about the warning ! Install e-x.x-q-xxxxxxx-yourdevice.zip

The basis for the custom ROM installation is the latest available Sony Xperia firmware, stock Android 6.0.1 (Marshmallow).

Even a downgrade from LineageOS 18.1 to LineageOS 17.1 requires a Factory-Reset - and thus all data and settings are irretrievably lost.

From this point of view, it is no problem to switch to /e/OS ‘Q’ v1.6. It’s the same installation procedure.

A new /e/OS ‘R’ instead of the tried and tested /e/OS ‘Q’ for the Xperia Z2 wouldn’t offer a significantly different user experience. In my eyes, the only important thing is that no matter which /e/OS version is made available, the ROM runs stably and continues to be supported permanently.

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@anon29344687 @piero thx for your quick replies…

the stock android level was firmware 23.5.A.1.291 flashed with flashtool as described in the wiki.

I am not very experienced in flashing - I still remember, when I destroyed 2012 my phone with flashing cyanogen… so I am very carefully, because the Z2 is really nearly new - also the battery holds more than a week in standby.

Factory reset is clear and no problem - but should I return to firmware 23.5.A.1.291 with flashtool? Is this more save?

and yes its clear, that a tested Q is still ok, but quite a lot of /e/ devices are already S - why castor stays on Q, when R is available since april 22 - https://forum.xda-developers.com/t/rom-official-lineageos-18-1-for-castor-castor_windy.4261491/

I installed LinageOS for microG 18.1 and could install Bromite - the basis of the /e/ browser - this solved my main problem playing DRM Live Stream News…

I hope also to get the banking apps working, as they are working in /e/ without any problems. So I think I just have to suffer under the design of the launcher and wait until the R build of Castor is ready…

[quote=“kultex, post:4, topic:46414”]

Sony Xperia Z2 Firmware Build number 23.5.A.1.291 is Android 6.0.1 Marshmallow. If you installed this build with the flashtool - where do you want to go back to?

What advantages do you hope to get from release ‘R’? Please name at least three serious advantages?


In the LineageOS statistics, the Z2 (castor) is listed in position 586 with 504 active LOS installations worldwide. Compared with position 1. gemini = 305875 active devices, this is a distant second. /e/OS is certainly used by significantly fewer users overall.

Why the e-team is currently holding on to the /e/OS-Q version can only be answered by the development department. But one reason could be that the Z2 (castor) is only used by very few users and therefore only enjoys a low priority. The available manpower will probably assign /e/ to more frequented devices.

By the way: there are alternative ‘launcher’. The /e/ user is not bound to the Blisslauncher.

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@anon29344687 I am on LinageOS 18.1 - which is R and I think, I cannot go back to /e/ Q - everywhere its recommanded not to go back from R to Q or from LOS 18.1 to 17.1 - maximum eventually over the stock firmware - like mentioned here:
https://community.e.foundation/t/motorola-x-play-xt1562-fails-upgrading-to-e015-q/29802/8

And what advantage do I get from R Release? - I could flash /e/ R without any problems over Linage 18.1 and use /e/ instead of Linage and probably 1 year longer support, because the /e/ Q builds will drop out next from /e/, I guess

As your firmware is based on “google marshmalow” android level (if it is latest available)
whatever existing /e/ version you choose, “n”, “o”, “p”, “q”, “r”, “s” will be right, even LOS 13, 14, 15, 16, 17, 18, 19, 20 All will be based on “mm” latest stock firmware

A contrario :
If the vendor OS is based on “google tiramisu” android level, you will be abble to install LOS 20 but not 19, 18, 17, 16, 15, 14, 13, nor /e/OS s, r, q, p, o, n, because none of them was based on a “t” stock firmware

@kultex
Sony Xperia Z2 firmware build number 23.5.A.1.291 is a complication-free Android 6.0.1 Marshmallow. Install it as the first step for a new installation of /e/OS Q | 17.1 Android 10.

Two examples

Here’s a comparable example:
The indestructible Samsung Galaxy S5 LTE (klte). Last available stock Android 6.0.1 (Marshmallow). I have already installed at least a dozen different custom ROMs on this device: from 7-Nougard (14.1) , 8-Oreo (15.1) , 9-Pie (16.0), 10-Q (17.1), 11-R (18.1) to 12L-S (19.1). Currently it runs with /e/OS R v1.6 | 18.1 | 11 ‘Red Velvet Cake’. With each new installation, I reinstalled the Samsung stock Android 6.0.1 as the first step. This is the basis.

BTW: Just because the official Android 10 support end date from Google is approaching, doesn’t mean it 10-Q Custom ROM can’t get security updates anymore. The /e/developers have the know-how to generate security updates for 10-Q from higher Android versions. Whether they have the time is another question.

Here too is an example:
I use a Samsung Galaxy Tab S2 SM-T813 with an excellently maintained LineageOS 17.1 with Android security patch level 12.2022. The 01/2023 update is expected in mid-January 2023. The 17.1 ROM is further developed and carefully maintained by an enthusiast who also uses the device himself. It also supports signature spoofing, so I can install the latest microG 0.2.26.22.23.16 manually. I haven’t seen a faster, better and more privacy-friendly custom ROM for the Tab S2 SM-T813 since /e/OS o.23-q support ended. The unofficial releases with LineageoS 16.0 and 17.1 offered elsewhere cannot hold a candle to this ROM.

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@piero thx for explanation…

Restore the device back to a well known stock OS also replace the security update patch date to an old one that can be usefull in case of recent devices when latest /e/'s related security patch is older than latest stock firmware installed is…

Thx @piero

Last question

From the Xperia z2, there is also a phone variante - only camera and screen differ a little bit. There is a R build available for the phone!
In linux, I would say, I could install the phone build without any problems on the phone. Would this be possible also with /e/ ?