[SOLUTION] No IMEI / Signal after downgrade Oreo 8.0 to Nougat 7.0

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sabpprook

Senior Member
Dec 8, 2011
269
374
Kaohsiung
I found a post explain how to get IMEI back.
original post: http://bbs.gfan.com/android-9272781-1-1.html

Two methods for S-ON or S-OFF device, please do it under Nougat 7.0 firmware installed.

S-ON
1. Reboot to TWRP recovery
2. Use the command below to erase persist partition
Code:
adb shell
dd if=/dev/zero of=/dev/block/bootdevice/by-name/persist

S-OFF only
1. Reboot to bootloader (not download)
2. Use the command below to erase persist partition
Code:
fastboot erase persist


Is that possible to downgrade without S-OFF??
Please watch my video, HTC 10 can downgrade in the same method!!!


PS. This video is for HTC One M9, please use Nougat RUU/firmware for HTC 10 to do downgrading.

https://www.youtube.com/watch?v=vJrNEsWVyOc
 
Last edited:

Wonders_Never_Cease

Inactive Recognized Contributor
Jul 10, 2013
2,740
1,552
Confirmed working on US/Dev Unlocked s-off/s-on devices... Nice find...:good::good:

Steps for s-on device:

1) Reboot to TWRP recovery
2) Install latest adb tools on your PC.
3) Plug in phone to PC. On PC run cmd prompt. Navigate to adb folder. Use the command below to erase persist partition on your phone:
Code:

adb shell
dd if=/dev/zero of=/dev/block/bootdevice/by-name/persist

4) Flash stock recovery
5) Relock bootloader
6) Run the RUU for your phone

Thanks @ssmud

Steps for s-off device:

1. Copy firmware zip to where your adb/fastboot is located
2. Reboot device into download mode
3. Connect phone to computer
4. Run command fastboot flash zip name of firmware.zip(run command twice if have failed message)
5. Do NOT restart device, immediately reboot to bootloader
6. Run command fastboot erase persist
7. Reboot to download mode, Flash RUU for your device IF available.

Alternative Untested but should work fine

1. Copy firmware zip to where your adb/fastboot is located
2. Reboot device into download mode
3. Connect phone to computer
4. Run command fastboot flash zip name of firmware.zip(run command twice if have failed message)
5. Do NOT restart device, immediately reboot to bootloader
6. Run command fastboot erase persist
7. Reboot to download mode, flash twrp for device
8. Format and wipe device
9. Flash backup of your devices region
10. Reboot

2.51.617.32 RUU

2.51.617.32 Firmware

Most other files for devices are located here
 
Last edited:

saxena.siddhu

Senior Member
Apr 14, 2011
87
24
Thank You!

Confirmed working on US/Dev Unlocked s-off device... Nice find...:good::good:


Steps for s-off device:

1. Copy firmware zip to where your adb/fastboot is located
2. Reboot device into download mode
3. Connect phone to computer
4. Run command fastboot flash zip name of firmware.zip
5. Do NOT restart device, immediately reboot to bootloader
6. Run command fastboot erase persist
7. Reboot to download mode, Flash RUU for your device IF available.

Alternative Untested but should work fine

1. Copy firmware zip to where your adb/fastboot is located
2. Reboot device into download mode
3. Connect phone to computer
4. Run command fastboot flash zip name of firmware.zip
5. Do NOT restart device, immediately reboot to bootloader
6. Run command fastboot erase persist
7. Reboot to download mode, flash twrp for device
8. Format and wipe device
9. Flash backup of your devices region
10. Reboot

Relevant Username.
 

firedown_3

Senior Member
May 15, 2012
68
19
I found a post explain how to get IMEI back.
original post: http://bbs.gfan.com/android-9272781-1-1.html

Two methods for S-ON or S-OFF device, please do it under Nougat 7.0 firmware installed.

S-ON
1. Reboot to TWRP recovery
2. Use the command below to erase persist partition
Code:
adb shell
dd if=/dev/zero of=/dev/block/bootdevice/by-name/persist

S-OFF only
1. Reboot to bootloader (not download)
2. Use the command below to erase persist partition
Code:
fastboot erase persist

Thank you
Confirmed working on HTC10 taiwan s-off device
 

fmedrano1977

Senior Member
May 1, 2009
2,189
522
San Antonio, TX
Will this work to go back to everything Nougat for those that flashed US unlocked Oreo RUU. I'm s-off but get error trying to flash Nougat RUU.

Sent from my HTC 10 using Tapatalk
 

Wonders_Never_Cease

Inactive Recognized Contributor
Jul 10, 2013
2,740
1,552
You cannot just flash Nougat ruu,as per instructions you have to flash firmware first if s-off... Please read second post...

Will this work to go back to everything Nougat for those that flashed US unlocked Oreo RUU. I'm s-off but get error trying to flash Nougat RUU.

Sent from my HTC 10 using Tapatalk


---------- Post added at 02:26 PM ---------- Previous post was at 02:21 PM ----------

2.51.617.32 Firmware and RUU links posted in 2nd post
 
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  • 55
    I found a post explain how to get IMEI back.
    original post: http://bbs.gfan.com/android-9272781-1-1.html

    Two methods for S-ON or S-OFF device, please do it under Nougat 7.0 firmware installed.

    S-ON
    1. Reboot to TWRP recovery
    2. Use the command below to erase persist partition
    Code:
    adb shell
    dd if=/dev/zero of=/dev/block/bootdevice/by-name/persist

    S-OFF only
    1. Reboot to bootloader (not download)
    2. Use the command below to erase persist partition
    Code:
    fastboot erase persist


    Is that possible to downgrade without S-OFF??
    Please watch my video, HTC 10 can downgrade in the same method!!!


    PS. This video is for HTC One M9, please use Nougat RUU/firmware for HTC 10 to do downgrading.

    https://www.youtube.com/watch?v=vJrNEsWVyOc
    24
    Confirmed working on US/Dev Unlocked s-off/s-on devices... Nice find...:good::good:

    Steps for s-on device:

    1) Reboot to TWRP recovery
    2) Install latest adb tools on your PC.
    3) Plug in phone to PC. On PC run cmd prompt. Navigate to adb folder. Use the command below to erase persist partition on your phone:
    Code:

    adb shell
    dd if=/dev/zero of=/dev/block/bootdevice/by-name/persist

    4) Flash stock recovery
    5) Relock bootloader
    6) Run the RUU for your phone

    Thanks @ssmud

    Steps for s-off device:

    1. Copy firmware zip to where your adb/fastboot is located
    2. Reboot device into download mode
    3. Connect phone to computer
    4. Run command fastboot flash zip name of firmware.zip(run command twice if have failed message)
    5. Do NOT restart device, immediately reboot to bootloader
    6. Run command fastboot erase persist
    7. Reboot to download mode, Flash RUU for your device IF available.

    Alternative Untested but should work fine

    1. Copy firmware zip to where your adb/fastboot is located
    2. Reboot device into download mode
    3. Connect phone to computer
    4. Run command fastboot flash zip name of firmware.zip(run command twice if have failed message)
    5. Do NOT restart device, immediately reboot to bootloader
    6. Run command fastboot erase persist
    7. Reboot to download mode, flash twrp for device
    8. Format and wipe device
    9. Flash backup of your devices region
    10. Reboot

    2.51.617.32 RUU

    2.51.617.32 Firmware

    Most other files for devices are located here
    14
    Oreo Downgrade Erase Persist Flashable Zip

    i can get in to download mode
    only if i connect the phone to the pc the pc tells me that it can not reconigze the phone

    Here is a flashable zip of the Erase Persist Partition command that I threw together..
    This will do the Erase Persist step automatically if you can flash it in Twrp.
    Maybe this helps others who have PC connectivity issues or are just too used to doing things the easy way...

    Erase_Persist_Oreo_Downgrade_Flashable.zip

    (untested by me, but should work as intended)
    Anyone who uses it, feel free to confirm... :good:
    7
    But why such an old ruu or firmware?

    Just to confirm

    - flashed 2.41.401.4 firmware
    - rebooted to bootloader
    - do command "fastboot erase persist"
    - reboot to download mode
    - flash twrp
    - full wipe and format, ignore the persist mount error
    - install nougat custom rom

    Done.... awesome. Thanks all involved, great job
    4
    Already did that without success.


    Already did that, when I start with the "adb shell" first, the screen stays in the same state that my previous screenshot.
    How about the flashable zip I posted?
    Tried that....?
    https://forum.xda-developers.com/showthread.php?p=75602484

    Sent from my Pixel 3 XL using Tapatalk