I solved my issue, it could help someone else...
One way from Android 8.1.0, to go to Android 9 and to Android 10 beta2 from my xXx_NoLimits_12.0_OP5_Oxygen_5.1.3_full.zip and twrp-3.2.1-x_blu_spark_v8.61-op5_op5t.img.
1- Go full OnePlus 5 stock : I used TOOL_ALL_IN_ONE_2.0.1.2 and the mauronofrio's fastboot ROM for OnePlus5 (OnePlus5Oxygen_23_OTA_029_all_1801292040_f50c278a6e154736-FASTBOOT.zip)
2- Using OTA update up to the last possible : 9.0.11
3- Download OB2 for OnePlus 5 from OnePlus website (OnePlus5Oxygen_23_OTA_064_all_2004231206_e6e62df77f104cc0.zip) and copy it to the root of internal memory. Apply it by local update.
4- Flash recovery (tested successfully with twrp-3.3.1-x_blu_spark_v9.110_treble-op5_op5t.img)
I will test the flash of twrp-3.3.1-1-cheeseburger-dumpling-mauronofrio.img
Thanks a lot to mauronofrio for all his devs.
Exact same problem, symptoms:
- after flashing latest twrp-3.4.0-1, recovery is not booted
- you can see black screen with blue indicator
MY DEVICE WAS ALREADY UNLOCKED
I will duplicate solution with few additions:
1. Go to Windows
2. System -
https://androidfilehost.com/?fid=746010030569970433
3. Tool -
https://toolaio.tk/download/
4. USB driver -
https://oneplususbdrivers.com/oneplus-5-usb-driver-download/
5. Open TOOL ALL IN ONE, you will be prompted to select device
6. Flash Factory Images, select file from step 2
7. We can load to Android 8 now
Next (I prefer doing it under linux):
1. Latest OTA -
https://www.oneplus.com/ru/support/softwareupgrade/details?code=PM1574156143164
2. Go to (OxegenOS) recovery
3. Sideload latest OTA
4. After install you'll have you Vendor **** (sorry)
Next
1. Latest TWRP -
https://eu.dl.twrp.me/cheeseburger/
2. Sideload whatever you want with it (LoS 19 for example)
3. Profit
Upd:
After installing LoS MicroG 19.1 with twrp-3.4.0 twrp stopped booting... so I flashed LoS recovery and enabled recovery upgrade during OTA in settings. If you want to sideload LoS ROMs than LoS recovery have sideload option. It can also sideload MicroG if ignore signature