Question Xperia 1 III Softbank A101SO issues Downgrading after a crossflash

[Samuël_Fab]

Hello everyone.
I bought a japanese Xperia 1 III (Softbank version A101SO) with Android 12 and I've searched for the 13 update but it turns out Softbank didn't release Android 13 on this phone yet.
So I decided to flash the KDDI version to it (with newflasher) and it worked.
But the problem is I got a very weak signal, a battery drain and the 4G rarely appears (always H or H+)
I tried to come back to the old original firmware but the phone won't boot after the flashing process (rollback protection)
The phone has a locked bootloader and it says it can't be unlocked so I wonder if you have a solution for me because I lost all hope right know.
If I can just go back to its original firmware (Android 12 from Softbank) that's all that I need right know.
Thak you for your answers.

 

[FiDra]

Unless you unlock your bootloader, otherwise, you cannot go back to Android 12 again. If your phone's config name 'Bootloader unlock allow' is No, then you have to stick around with KDDI Android 13 fw.

 

[Samuël_Fab]

Unless you unlock your bootloader, otherwise, you cannot go back to Android 12 again. If your phone's config name 'Bootloader unlock allow' is No, then you have to stick around with KDDI Android 13 fw.

Thanks for your reply! I'll have to stick with it then...
But can I flash the Softbank modem to it to have a better signal coverage?

 

[FiDra]

I think cross flashing is okay but you need to do some search to make sure you flash all needed files to prevent boot loop.

 

[Samuël_Fab]

I think cross flashing is okay but you need to do some search to make sure you flash all needed files to prevent boot loop.

crossflashing works but the problem is the Signal and the battery drain.
is there a way to flash other modem files to the phone?

 

[FiDra]

Try newflasher, you can search the forum for the guide.

 

[Samuël_Fab]

Try newflasher, you can search the forum for the guide.

Newflasher is the tool to flash the roms.
I know how to use it since I've crossflashed my Xperia 1 III with another region FW using it.
My question is: is there a way to flash different modem files (and other important files) to the phone with a different region rom to fix the signal and battery drain issues?

 

[bentree]

Newflasher is the tool to flash the roms.
I know how to use it since I've crossflashed my Xperia 1 III with another region FW using it.
My question is: is there a way to flash different modem files (and other important files) to the phone with a different region rom to fix the signal and battery drain issues?

Yes just keep the .Sin files that you fish to flash and remove the rest from the rom folder. And make sure when prompted by Newflasher to "keep user data".

 

[Samuël_Fab]

Yes just keep the .Sin files that you fish to flash and remove the rest from the rom folder. And make sure when prompted by Newflasher to "keep user data".

ohh! thanks for your tip!
I want to ask you:
do you know the name of the modem files that control the network?

 

[bentree]

ohh! thanks for your tip!
I want to ask you:
do you know the name of the modem files that control the network?

Modem.Sin is the file you are after.

 

[Samuël_Fab]

Modem.Sin is the file you are after.

So I've successfully flashed the modem sin file but there's a problem with the camera.
It refuses to launch and the Telephoto lenses are moving all the time (with the noise of the lens moving).
But the signal is back at 4G.

 

[bentree]

So I've successfully flashed the modem sin file but there's a problem with the camera.
It refuses to launch and the Telephoto lenses are moving all the time (with the noise of the lens moving).
But the signal is back at 4G.

no idea with that one... sorry

 

[Samuël_Fab]

no idea with that one... sorry

I guess flashing it with other modem sin files don't resolve the issue.
I need to wait for the Softbank Android 13 (if it will be released one day...)

 

[Bachtran24]

Thanks to you and people on this post, I've been able to flash fw 61.1.E.5.215 into my A101SO and fix mobile connection and camera by flash .sin file from A101SO android 12 fw. If you still struggle with the camera, let me know. I've seen improvement with battery life and mobile signal, the only let down is netflix wont install from playstore nor playback at full fidelity if I install with apk

 

[Bachtran24]

I guess flashing it with other modem sin files don't resolve the issue.
I need to wait for the Softbank Android 13 (if it will be released one day...)

 

[Ainz_Ooal_Gown]

Thanks to you and people on this post, I've been able to flash fw 61.1.E.5.215 into my A101SO and fix mobile connection and camera by flash .sin file from A101SO android 12 fw. If you still struggle with the camera, let me know. I've seen improvement with battery life and mobile signal, the only let down is netflix wont install from playstore nor playback at full fidelity if I install with apk

what file did you flash for the Camera?

 

[Bachtran24]

what file did you flash for the Camera?

After I succesfully flashed a bootable fw (XQ-BC72_Customized SEA_61.2.A.0.447 for me), I flash these .sin files from A101SO_SoftBank JP_61.1.E.5.215 right after. The camera problem only rise if you also flash modem_X-FLASH-ALL-4BA8.sin