I have a
OnePlus 7Pro (GM1917) that was working fine for a long time with
OOS 10.3.8. Its bootloader is unlocked, and it was rooted. I hadn't upgraded it for a long time, and recently I decided to flash an A11 ROM:
OOS 126.96.36.199.GM21AA. At that point, I lost all ability to access the
I know that there can be similar issues with such an A10-to-A11 upgrade, and that many of these issues are solvable. However, I have investigated and tried many things to fix this, to no avail, and I fear that my problem goes deeper than those issues and might not be fixable. But I'm hoping that there might still be something which I haven't tried that could fix my problem.
Here is a detailed description of everything I did, how it all failed, and everything I have tried so far to fix it ...
After the A10-to-A11 upgrade, my device went into a permanent boot loop when trying to boot to
I then did
fastboot boot twrp-3.6.0_11-0-guacamole.img (which is the version of TWRP that is meant to work with this
OOS 188.8.131.52 ROM), and this indeed put me into TWRP. However, the
/data partition is inaccessible. Whenever I try to format
/data, I consistently get these messages:
Failed to mount /data (Invalid argument) Unable to recreate /data/media folder. Unable to mount storage Unable to mount /data/media/TWRP/.twrps Unable to wipe data
I then went back to the bootloader, and I ran these commands:
fastboot erase userdata fastboot format:ext4 userdata
These commands successfully run with no error messages. However, when I then go back into TWRP,
/data is still inaccessible, and I get the same error messages that I listed above when trying to format
I then tried to decrypt
/data, but when I do so, it asks for a password, and I have no idea what password to give. I never used any password on the device in the past. I am not allowed to decrypt
/data without a password.
So, I decided to use the
MsmDownloadTool to reflash my device back to
OOS 10.3.8. This works fine with a different
GM1917 device that I have (but which I never tried flashing to
OOS 11). However, with this particular device, after going into
EDL mode, I am told that I am "Connected", but a couple seconds later it gives me the "Sahara Connection Failed" message. I have double-, triple-, and quadruple-checked the device drivers, and it indeed is showing that the
Qualcomm qds 9008 driver is properly installed and active on the PC. Furthermore, as I mentioned, I have no problem using
MsmDownloadTool on that same PC with another
I then went further: I extracted
payload.bin from the
OOS 184.108.40.206.GM21AA installation bundle, and I extracted all of the
*.img files. I flashed
boot.img via fastboot and retried everything that I mentioned above, but nothing has changed.
I then went and flashed all of the
*.img files via fastboot. However, still nothing has changed.
When flashing the set of all
*.img files, in some cases, I was told that the file is critical and cannot be reflashed. I then ran these two commands ...
fastboot flashing unlock fastboot flashing unlock_critical
... but in both cases, I am told that the device is already unlocked. Trying to flash all of the
*.img files again gave me the same results: i.e., some got flashed, and others were not flashed due to being "Critical".
Also, some of the items I flashed were said to be "sparse", and their flashes were flagged with warnings, but as far as I can tell, they seem to have been flashed anyway.
In the end, I still go into a bootloop when booting to
/data partition is still inaccessible, and
EDL mode still does not function.
Do these problems with
EDL and everything else mean that my device is somehow permanently damaged? Or are there perhaps one or more additional things that I can try in order to restore it to some sort of working state?
Thank you in advance for any thoughts or ideas.