[OnePlus 6T  Questions & Answers] Deleted member 10054198:
Hi,

I somehow bricked my op6t, but managed to recover it with this steps, which i will paste here, these aren't mine, copied to a txt file then here i will help you mate. After this process, you must restore IMEI, and AFTER THIS WHEN YOU WILL LOAD ANY OTHER OOS IT WILL APPEAR A MESSAGE: "INVALID NV's...."

Also i must specify that i had MODEM_A&B, MODEMST1&2 BACKED UP, I RESTORED THEM BUT THE "INVALID NV's...." persisted..... Good luck!

"The only solution is to use smt mode inside msmdownloadtool, which will restore persist partition, but with some disadvantages.

Be aware that you WILL LOSE YOUR IMEIs and WIDEVINE L1, use it at your own risk.

If you decide to do it (remember you WILL LOSE YOUR IMEIs and WIDEVINE L1!) follow this:

1.- Run MSMDownloadTool.

2.- Click on Verify and wait till it says "MD5 Check OK!".

3.- Then click on SMT Mode.

4.- Then click on Start like you would normally do with upgrade mode.

5.- The you need to enter as password "te123" and select your phone's capacity.

6.- If it says something like "Port disabled by user", go to the top left corner and click on "SMT", "COM Setup" and check everything, then click on the left button, and retry steps 4-5.

7.- When the process finishes the phone won't reboot, so you'll need to hold VolumeUP+Power until it powers on, then wait around 5 minutes and your phone will be back to life!!

8.- If you have an IMEI backup, just follow this guide (https://xdaforums.com/oneplus-6t/how-to/guide-oneplus-6t-unlock-bootloader-t3851789) (I don't know if this is the correct way to post links)

I hope you get your phone fixed.

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Restoring an EFS Backup?

If by chance you end up with a corrupt EFS partition all you need to do is flash the files back to your device using fastboot.

Boot into fastboot mode (power + volume up) and connect your phone to your PC via usb cable.

Keep modemst1.bin and modemst2.bin (backed up earlier) on your desktop and open command window there.

These fastboot commands will restore the files:

Code:

fastboot flash modemst1 modemst1.bin

Code:

fastboot flash modemst2 modemst2.bin

Reboot your device.

Code:

fastboot reboot

Now disconnect phone from PC. Your IMEI should be back.

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Making an EFS Backup

?

All too often, we've seen folks who have a corrupted or missing EFS Partition. This results in your IMEI being lost and no cellular activity on the device at all. This can be a royal PITA to fix, and some folks haven't been able to fix it at all. You can take a precautionary measure to safeguard yourself against this by taking a couple of minutes to back up your modemst files.

Download & Open up Terminal Emulator on your phone from here

Once it's open you'll be greeted with a command line prompt, in which you can enter text commands, the first thing you need to do is enable root access by entering this line (press the enter key on your on-screen keyboard after each command to issue it):

Code:

su

If this is the first time you've used Terminal Emulator a Superuser or SuperSU popup will appear, make sure you grant root access.

Now enter these two commands:

Code:

dd if=/dev/block/sdf2 of=/sdcard/modemst1.bin bs=2048

Code:

dd if=/dev/block/sdf3 of=/sdcard/modemst2.bin bs=2048

This will place two files (modemst1.bin & modemst2.bin) on your internal storage.

Make sure you copy them to your PC and Cloud immediately so that you have a backup there to use if you need to restore it in future.

That's it !! In case you ever need to restore Nanroid or EFS Backups, please continue and follow the next post..."