Root downgrading rom issues

[SavageRobot]

So I have decided I want to re-root my phone and so with my build being ..290 or something rather than the ..5.. it needs to be to root I looked online and downloaded C6903 14.1.G.1.534 EE UK 1276-2219_R9A the phone went into bootloop when I didn't wipe cache etc (one of the guides said that it would be OK) so I tried it again clearing everything and it worked....well sort of.
It didn't have any signal and wouldn't let me log into Google etc. After investigating it turned out my IMEI had been changed to all 0's. Thinking it might be a dud ftf I tried installing the general UK file C6903 14.1.G.1.534 Generic UK 1276-0875_R9A...no luck, same thing. So in the end I had to download and install C6903 14.2.A.0.290 EE UK 1276-2219_R2B. Seems to be working now and IMEI is back etc, got signal but it didn't redownload all my apps and setting etc.
Anyway. Any suggestions what I may have done wrong and how to downgrade so that I can root?

 

[El Presidente]

Yeah, for some reason, downgrading from a .290 firmware/ROM breaks the radios.

There is a fix, give me a couple of seconds and I'll dig it out.

 

[SavageRobot]

Thanks El Presidente. Did you manage to track to fix? it makes no difference if I haven't unlocked the bootloader does it?
Also slightly off topic, let me know if I should start a new thread for this, but I tried to backup using CWM but the Z1 isn't listed in the phone models, in fact, there are no Sony phones I think. Am I missing something?

 

[El Presidente]

Posting about recovery here is cool, it's your thread.

I'm not sure if CWM is officially supported on the Z1, when I installed recovery, I used this: Xperia ZU & Z1 recovery for locked bootloaders v4, Fully working! BETA STAGE[19/10] - xda-developers

I searched for about 10 minutes, then fell asleep, sorry.

I've a couple of things to do today, so if you can hang fire for a bit, I'll have another look later.

 

[SavageRobot]

Great I'll have a go at that then thanks.
Haha, yea no problem. No rush, I think will have to wait until tomorrow to start trying to do anything about it anyway

 

[El Presidente]

[STOCK][C69XX][4.3] Update to 14.2.A.0.290 [Root & XZDR][LB/UB][16/1/2014] - Page 109 - xda-developers

There you go, looks like you have to downgrade in steps for it to work.

I can't confirm, as I've never done it.

Do you want to install a ROM or are you just looking to backup?

 

[SavageRobot]

Thanks I will have a gander later tonight / tomorrow, looks like a hell of a work around just to get the thing rooted. I will be able to the update ROM back to current as long as I do it OTA and keep root won't I reading forums etc.
I'm not particularly looking to install another ROM as there aren't that many about and I don't know how stable they are etc. With my old GS2 I practically installed a new ROM every week but I'm quite happy with Sony's UI. I just really want ROOT access for apps etc and as up-to-date ROM as I can have lol. Do you know of any KitKat ROMs that are stable and have things working smoothly yet?

 

[El Presidente]

I've not really followed AOSP development for the Z1. My bootloader isn't unlockable and to be honest even if it was, like yourself, I'm more than happy with the Sony UI anyway (you need to unlock the bootloader for non stock ROMs).

Downgrading, rooting, installing CWM/TWRP, then a custom ROM might be easier than the 2 step downgrade process? Up to you.

I was using Monx's ROM with no issues whatsoever, it's as stable as stock for me.

Just one word of advice, no matter what you do, don't update busybox if you install the recovery. I don't know the technical ins and outs, but because of how recovery works on the Z1, it needs its own busybox to work properly and as I found out, updating busybox deletes the recovery.

 

[SavageRobot]

Could I for instance, just straight flash Monxs ROM from the stage I'm at now and have should have no issues and be rooted?

 

[SavageRobot]

I think I will have a go at that ROM but I don't really understand his instructions. Can I basically downgrade the ROM as prev posted. Then update this HONAMI_430_136_MONX_040001P_REL.zip via the flashtool? Would that work? If not, how do I boot into recovery on Z1? I can't find it online. Can you talk me through a little more clearly? Thanks.

 

[El Presidente]

Because your bootloader is locked and the way the recovery works, it can't write to certain partitions, most importantly the boot partition (kernel) and the baseband (radio).

So after you've flashed the ROM in recovery, you need to flash the partitions which recovery can't touch with flashtool.

Anyhoo...

1. Downgrade to a rootable version (.518 or .534) using flashtool
2. Install the Dual Recovery
3. Copy the ROM.zip to your SD Card
4. Boot into the recovery by powering off the device, turning on and waiting for the Sony logo to appear. Watch for the green LED to appear, as soon as it does, hold the up or down volume button. One is for TWRP, the other is for CWM (can't remember which, sorry).
5. Backup your current ROM
6. Factory Reset
7. Install the Monx zip.
8. Head back to the main menu in recovery, then turn off the handset using the applicable option in recovery. Select no if it asks about a recovery installation warning.
9. Connect the phone to your PC and put it in to Flash mode
10. Using Flashtool, flash a corresponding ftf file excluding the System and TA Partitions (keep everything else) and without wiping anything. For example, if you've just flashed a .290 zip file, flash a .290 ftf.
11. Once Flashtool has done what it needs to reboot and you should be good to go.

Point 10 is very, very important as flashing the wrong stuff in flashtool can hard brick the phone. Does that all make sense (especially point 10)?

 

[SavageRobot]

OK, I have a few questions now and hit some snags and a little worried about carrying on now. Last night I tried to downgrade to .257 from .290. Still lost my IMEI!! I think it just doesn't want me to root ha. Could it be because I am on EE and there isn't a 257 file EE? I had to just use the Universal UK one?

In above instructions, do I just go straight to .534 and doesn't matter about breaking radios? Also, I assume that as soon as I go down to a rootable version I then root before doing anything else?
When installing dual recovery, it says to extract to C:\ (or somewhere on the computer) what file do I need to run on computer and shouldn't I be putting them somewhere on the phone? I'm sorry but I just don't understand his instructions very well.
Is the zip in the above post the correct one (Honami...)? If so, how do I know if that is .290 etc?
Sorry about all the noob questions but this seems a lot more difficult to how did it for Samsung :/

 

[El Presidente]

Sorry, I had a really busy weekend at work.

As long as it's from the same region as your handset, you can pretty much flash any FTF, so the generic UK will be fine.

Technically, it shouldn't matter about the radios, from what I can read, when you get back to a 4.3 ROM, everything should work again. As I said before, I haven't had to downgrade to 4.2.2 yet, so I can't personally confirm.

And yeah, root before doing anything else (I didn't put that in the steps as it's a pre-requisite for the recovery).

To install the recovery, you need to extract the zip file to your PC, connect your phone, then run the batch file on your PC to install the recovery.

That looks to be the right file, yeah. You can tell if it's a .290 or .136 as the ROM zip will have that in the name. The one you linked to is 430_136 so you'd need a .136 ftf.

Does that help?

 

[SavageRobot]

No worries, don't envy you having to work the weekend.
Well looking here [FTF] C6902 & C6903 & C6906 & C6943 FTF Mega Collection - xda-developers there isn't specifically a UK region for .136 firmware released yet. Should the Global one be OK, or if not, Central Europe? Do you know what the differences are between them? Is it just the bandwidth etc that signal is collected?
Thanks for all your help, hopefully after this I should get it...

 

[El Presidente]

Par for the course when you work shifts unfortunately, but as of Thursday AM, I'll be off for 17 days so one weekend in 3 is a small price to pay.

Anyhoo, technically, you could use the Central European FTF. However, there were some incompatibility issues with the Central European FTF for the 290 ROM, so you might be better off waiting for .136 UK ftf to be released?

 

[SavageRobot]

As it happens I plugged the phone in today and looks like EE have finally pushed out the .136 update. Will just wait for the update to hit the list here [FTF] C6902 & C6903 & C6906 & C6943 FTF Mega Collection - xda-developers thanks for your help and we will see if I need some more when we get there.

 

[El Presidente]

Great, happy to help!

Let me know when you go for it.

 

[SavageRobot]

Still can't see an ftf for the .136 ROM for EE or UK. Is there somewhere these are sourced from I could grab it myself do you know?

 

[El Presidente]

Still can't see an ftf for the .136 ROM for EE or UK. Is there somewhere these are sourced from I could grab it myself do you know?

I don't think there is one. Have EE even released the update?

 

[SavageRobot]

Yes they released it, I think it was a month or so I was able to upgrade. God knows, will just keep on waiting.

 

[El Presidente]

You can actually make the ftf yourself, you may even have the files needed already.

Did you do the update OTA or via PC Companion?

 

[SavageRobot]

You can?? Never knew that. I used pc companion.

 

[El Presidente]

[GUIDE] Download ANY firmware customization from Sony & create an FTF with Flashtool - xda-developers

There you go, have a read of that. If you're lucky, the required blob files should still be in the PC Companion folder.

I created my own for the old .257 update.

 

[SavageRobot]

Brilliant thanks. I'll take a look tomorrow.

 

[El Presidente]

Brilliant thanks. I'll take a look tomorrow.

That guide looks a little incomplete actually.

I'll have a look and see if I can find the one I used which goes in to a bit more detail.