Disappointed with Oreo rom (2.31.400.6), I decided to downgrade my phone to Nougat (1.27.400.6). I thought things would be simple, but as you have already guessed, I failed. S-OFF doesn't work in here, installing old Viper Nougat rom doesn't let me pass the settings screen. To be worse, I even wiped my 2.31.400.6 nandroid backup, so I flashed that of 2.31.709.1, and I could boot my phone.
I searched xda again and found someone says 'Downgrading with SDCard method works even in S-ON and unlocked bootloader. It even wipes everything.' I tried, but fastboot told me there is '19 RU_MAIN_VER_FAIL os-version in android-info missing...' error.
I thought it was happened because the bootloader is not relocked, so I typed 'fastboot oem lock.' However, the same error occurs.
I gave up, so I typed 'fastboot flash unlocktoken Unlock_code.bin' command to get back to unlocked mode, but the worst thing in my HTC life ever happened.
I found the situation is very similar to this guy(https://forum.xda-developers.com/u11/help/help-htc-u11-brick-t3704765). However, the situation is worse; The problem is,
1. There is no RUU for 2.31.400.6.
2. From Oreo bootloader, it is known that we're not able to use 'fastboot boot' command, even with stock recovery.
Now, I can't boot to TWRP recovery because the phone thinks the partition was corrupted, when I try to boot into normal mode, it says 'Your storage is now locked. Please put the password. ## attempts left until your storage gets wiped' blahblah... Even if I wipe my data partition, I don't think it will ever boot because it is 709 rom, not my 400 rom.
Do I have to wait until RUU of 2.31.400.6 gets appeared? Is there anything I can do?
I searched xda again and found someone says 'Downgrading with SDCard method works even in S-ON and unlocked bootloader. It even wipes everything.' I tried, but fastboot told me there is '19 RU_MAIN_VER_FAIL os-version in android-info missing...' error.
I thought it was happened because the bootloader is not relocked, so I typed 'fastboot oem lock.' However, the same error occurs.
I gave up, so I typed 'fastboot flash unlocktoken Unlock_code.bin' command to get back to unlocked mode, but the worst thing in my HTC life ever happened.
Yes, I didn't turn the 'Allow OEM unlock' mark in the developers option on. I searched once again to do something, but I think I just made a nice red brick.writing 'unlocktoken'...
(bootloader) flash unlocktoken
(bootloader) [KillSwitch] : /dev/block/bootdevice/by-name/frp
(bootloader) [KillSwitch] Last Byte is 0X00, disable unlock
(bootloader) [KillSwitch] oem unlock Turn Off!
I found the situation is very similar to this guy(https://forum.xda-developers.com/u11/help/help-htc-u11-brick-t3704765). However, the situation is worse; The problem is,
1. There is no RUU for 2.31.400.6.
2. From Oreo bootloader, it is known that we're not able to use 'fastboot boot' command, even with stock recovery.
Now, I can't boot to TWRP recovery because the phone thinks the partition was corrupted, when I try to boot into normal mode, it says 'Your storage is now locked. Please put the password. ## attempts left until your storage gets wiped' blahblah... Even if I wipe my data partition, I don't think it will ever boot because it is 709 rom, not my 400 rom.
Do I have to wait until RUU of 2.31.400.6 gets appeared? Is there anything I can do?
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