OnePlus 6T - Can't unlock bootloader nor get into Android

[AOnePlus6TDestroyer]

My OP6T had Ubuntu Touch (equivalent to Android 9) installed on it. When it broke, I tried to flash TWRP (version 3.3.1) to clear and reinstall Ubuntu Touch. For some reason it wouldn't boot, so I foolishly decided to flash TWRP onto every single partition. This only succeeded in breaking recovery mode. Following some advice I used the 6T MsmDownloadTool v4.0.58 (OOS v9.0.11), which fixed recovery mode, but not Android - it just showed the booting animation in a infinite loop (bootloop).

I've attached an image I found online showing the screen: bootloop

The issue is that I cannot flash in fastboot mode as the bootloader was relocked by MsmDownloadTool, *and* I cannot get into Android to enable OEM mode/USB debugging. I seem to have encountered a paradox where fastboot mode requires the permissions to be enabled in Android, but I can't boot to Android to enable those permissions, nor can I flash anything else to fix Android.

Is this possible to solve?

 

[rogerrulez]

My OP6T had Ubuntu Touch (equivalent to Android 9) installed on it. When it broke, I tried to flash TWRP (version 3.3.1) to clear and reinstall Ubuntu Touch. For some reason it wouldn't boot, so I foolishly decided to flash TWRP onto every single partition. This only succeeded in breaking recovery mode. Following some advice I used the 6T MsmDownloadTool v4.0.58 (OOS v9.0.11), which fixed recovery mode, but not Android - it just showed the booting animation in a infinite loop (bootloop).

I've attached an image I found online showing the screen: bootloop

The issue is that I cannot flash in fastboot mode as the bootloader was relocked by MsmDownloadTool, *and* I cannot get into Android to enable OEM mode/USB debugging. I seem to have encountered a paradox where fastboot mode requires the permissions to be enabled in Android, but I can't boot to Android to enable those permissions, nor can I flash anything else to fix Android.

Is this possible to solve?

 

[rogerrulez]

You can try booting with the twrp.img. "fastboot boot name.img" using that ADB command. If that does not work the only other option is to completely retore your phone using msmdownload tool. This method will also depend on whether you have the international version or the T-Mobile version as there are different approaches depending on the type of phone. Read and study carefully how to proceed. If the msm tool does not work I'm pretty damn sure there are no other options.

 

[Brettroth]

You can try booting with the twrp.img. "fastboot boot name.img" using that ADB command. If that does not work the only other option is to completely retore your phone using msmdownload tool. This method will also depend on whether you have the international version or the T-Mobile version as there are different approaches depending on the type of phone. Read and study carefully how to proceed. If the msm tool does not work I'm pretty damn sure there are no other options.

He can't boot into anything with bootloader locked. This is why msm tool sucks and people should stop recommending it for any little problem.

 

[Brettroth]

Only option now is to use msm tool again and hopefully get something working

 

[rogerrulez]

Even with the bootloader locked you still should be able to boot the recocery image.

 

[rogerrulez]

I have the 6T and 7T Pro. When I messed up my 6T my only hope was the msmdownloadtool. But make sure it's the right one.

 

[rogerrulez]

When I had to use the msm download tool it did lock the bootloader. But I was able to unloack it again from the ADB command prompt at the bootloader screen by typing fastboot oem unlock. But this can only be done if it is set in developer options.
I spent alot of time trying to figure it out but later found outthat I was using the wrong msm tool.
Good luck. I hope you get it and running again because the 6T is still a very good phone.

 

[AOnePlus6TDestroyer]

He can't boot into anything with bootloader locked. This is why msm tool sucks and people should stop recommending it for any little problem.

Are there more suitable tools for fixing a broken recovery mode? It did successfully do that.

 

[AOnePlus6TDestroyer]

Even with the bootloader locked you still should be able to boot the recocery image.

How?

When I had to use the msm download tool it did lock the bootloader. But I was able to unloack it again from the ADB command prompt at the bootloader screen by typing fastboot oem unlock. But this can only be done if it is set in developer options.
I spent alot of time trying to figure it out but later found outthat I was using the wrong msm tool.
Good luck. I hope you get it and running again because the 6T is still a very good phone.

Thank you! And yes, I tried that command but it is probably unset in the developer options (which I cannot reach, as Android isn't working anymore). I guess I'm using the incorrect version - how do you identify the correct one? I think I've used both the T-Mobile one and the other. I don't think the phone is T-Mobile, but I'm not sure how to identify whether it is or not.

 

[rogerrulez]

It is very easy to convert a t-mobile variant to the international version. If you bought the phone used you would not know. One tell tale sign could be if you sim card holder supports either one or 2 sims. But that's not a sure way either because you can buy a replacement sim card holder. The fastet was would be to look up the IMEI # and see what variant of the 6 you have.
As for the msm tool you would needd a modified version of that tool. You first use it to downgrade to Android 9. Then you have to upgrade that verion of android 9 to a slightly higher version before you are able to fully upgrade feely to 10 than 11 if you wanted.
If you have the international version pretty much and version of the msm tool would work but a modified version would be best.
However, the first step is to find out which variant you have.

When you used the msmdownload tool which version did you use, and did it finish the job ?

 

[rogerrulez]

If you have the t-mobile vesion there is a thread on here that gives you step by step instructions to convert from t-mobile to international along with the links to download the software. And even the modified version will know what variant you have simply by not working.

 

[rogerrulez]

If you are able to get into the bootloader than you have a great chance of fixing your phone. Your phone is bootlooping so that tells me you can access the bootloader screen.

 

[rogerrulez]

When I bricked mine I thought it was gone forever, I spent several days working on it but I was able to restore it. But I would never use the ubuntu rom on any phone that I care for.

 

[rogerrulez]

When you are at this level it is very important you proceed with caution and don't just start flashing anything you can find. It will nake matters much worse.

 

[Brettroth]

Even with the bootloader locked you still should be able to boot the recocery image.

Wasn't sure about that. If that's the case, can you also flash from twrp then?

 

[rogerrulez]

Wasn't sure about that. If that's the case, can you also flash from twrp then?

No. Not without an unlocked bootloader. But booting into twrp would give you the ability to flash a ROM tho.

 

[Brettroth]

No. Not without an unlocked bootloader. But booting into twrp would give you the ability to flash a ROM tho.

That's what I meant. Flash a ROM from twrp. Ok so if that works this guy can fix everything from there. Gonna be a hassle tho. Instead of rebooting to recovery I think you would have to shut off phone and fastboot boot back into twrp to change slots right?

 

[Brettroth]

Somehow I feel like that won't work but I'm not locking my bootloader to test it

 

[AOnePlus6TDestroyer]

The fastet was would be to look up the IMEI # and see what variant of the 6 you have.

I'm afraid I can't' find it... It is dual-sim though.

When you used the msmdownload tool which version did you use, and did it finish the job ?

I used a few - both T-Mobile and not. They all succeeded with (seemingly) no error, but didn't fix the bootloop.

If you have the t-mobile vesion there is a thread on here that gives you step by step instructions to convert from t-mobile to international along with the links to download the software. And even the modified version will know what variant you have simply by not working.

I see, but won't that need me to be in Android to be able to run the software?

If you are able to get into the bootloader than you have a great chance of fixing your phone. Your phone is bootlooping so that tells me you can access the bootloader screen.

Yup, fastboot and recovery mode work fine. The bootloader is locked though, else installing TWRP, etc. would be easy.

When you are at this level it is very important you proceed with caution and don't just start flashing anything you can find. It will nake matters much worse.

Yeah...

Even with the bootloader locked you still should be able to boot the recocery image.

It doesn't do it automatically. Is there another way to boot it?

Somehow I feel like that won't work but I'm not locking my bootloader to test it

As far as I can tell there's no way to flash TWRP without unlocking the bootloader. And there doesn't seem to be any way to do that without getting into Android. And I can't get into Android...

Someone else suggested using this tool (https://github.com/bkerler/edl) as a last-ditch attempt. I'm going to give it a try and hope for the best!

Thank you both for your suggestions.