[Android Q&A, Help & Troubleshooting] Japeroen:
Hi all,

tl;dr: Tried to hard unbrick my Oneplus X, which was partly succesful (no OS is installed in the process, while there should be). I am now stuck with no OS and only the Oneplus recovery. I want to install an OS, but it says my bootloader is locked. To unlock it, I need an OS ==> vicious circle.

Full story below:

Recently I've decided to reinstall LineageOS on my Oneplus X because I had quite some problems with it (battery drain, apps crashing, wifi slow to connect, ...). I've done it like 5 times before on this device for various reasons, so I didn't expect any problems. I had LineageOS 14.1 and TWRP 3.0.3 installed. When I wiped everything, I wanted to flash the ROM I had ready using TWRP. However, gave an error number 7, saying that the ROM is not compatible for the device, which I am sure was. Remembering I had a similar issue a while back, I installed flashed an updated version of TWRP (3.2.2) using TWRP itself. That was successfull, but here's where the trouble began.

I noticed that TWRP didn't recognise any storage (Internal storage, SD card and USB-OTG all showed up as 0 MB) any longer. Neither could I mount any of the storages. I've tried a lot of things to solve this. After a while, I decided that the only hope left was the 'mega unbrick guide' (https://forums.oneplus.com/threads/guide-mega-unbrick-guide-for-a-hard-bricked-oneplus-x.417648/) which claims to be able to recover any device, unless it has a hardware problem. I got good hope as I got near the end of the guide. The last step says 'Disconnect phone from PC and boot into system', but here I got stuck on the Oneplus boot logo, making me think that there is no OS installed on the device.

I can still access the recovery using power button and volume down, but the recovery that the mega unbrick guide installs, is the limited Oneplus recovery. It allows to install a ROM from the local storage, or from USB using adb sideload. When I try option 1, nothing happens, no new screen opens or anything. When I try option 2, I enter the adb sideload mode which would normally allow me to sideload a ROM using my pc. My pc confirms I'm in adb sideload mode, and I try to sideload a ROM. It starts fine, but after a few seconds, it says 'Installation failed'. I've tried stock OOS, latest OOS as well as LineageOS 14.1 that was installed before.

Another thing that I can do in the Oneplus recovery is rebooting into fastboot mode, where I should be able to flash the recovery of my choice. Again, my phone confirms I'm in fastboot mode and I try to flash or boot TWRP recovery, but I get the message: 'FAILED (remote: Device not unlocked cannot flash or erase)'. Okay, seems like the bootloader is still locked, so I should just go and unlock it using 'fastboot oem unlock'. This gives the message: 'FAILED (remote: oem unlock is disabled)'. I've been searching around a lot on the internet, and it seems like the only way to enable oem unlock, is in the OS itself in the developer settings. But the problem is, I have no OS and cannot install one because the bootloader is not unlocked... So I'm stuck in this vicious circle.

I've been searching on the internet for hours and starting to lose hope. At this point, I would be happy if I can just have any OS (OxygenOS or LineageOS or something else) running. If I have that, I should be able to take it from there.

Any help is much appreciated. Thank you very much.

Kind regards,

Jeroen