The OS of my OnePlus 5T was LineageOS 15.1(20180820) before August 12, 2019. After almost a year of using it, it was infected by a pop-up-out-of-nowhere ads virus and it was immensely annoying when I was in the flow doing what I love on my phone.
Therefore, I made up my mind to upgrade my phone's OS to LineageOS 16.0 to get rid of the virus and embrace the sweet Android Pie.
And that's when in succession I encountered the "recovery black screen blue led" issue which drove me mad and almost threw my phone to some sharpshooters to get repaired.
Followings are what I did to my phone OnePlus 5T when it's in "recovery black screen blue led" situation which to me was also a status of brickish phone :
Be prepared:
A. OnePlus 5T official anti-brick firmware (dumpling_43_H.06_171225.ops was what I found then) and the exe (MsmDownloadToolV4.0.exe, which was included in the precedent firmware compressed files) to flash the firmware into the phone.
C. OnePlus 5T power off.
Here we go:
- Open MsmDownloadToolV4.0.exe.
- Connect the phone to PC with only holding the Volume Up. It's ready when the MsmDownloadToolV4.0.exe shows "Comdevice"(Com设备) and then hit the “Start”.
- Flash OnePlus 5T official anti-brick firmware to the brickish phone via MsmDownloadToolV4.0.exe. After this, you'll get a phone like you first bought.
- Reboot it and then update its OS to the latest version which I got was 201905 version from the OnePlus 5T official OTA push. (My phone was already "OEM unlock" when I did this. ) I think this procedure was essential so that it sent me to the right path towards LineageOS 16.0.
- Follow the instructions from LineageOS.org for OnePlus 5T which you can find here to do the real work on your OnePlus 5T.
I backed-up all the important stuff in my phone's storage and regarded it as a brick and tried the above several times. In the end, I did it! My phone now is the latest version of LineageOS (Android 9.0 August 15, 2019) which I keep updated via OTA every day now if it has new push to me in the Settings.
I wrote these for me and those who had the similar situation for future reference.
