[ASUS ROG Phone 5 / 5s] Nyda:
Recently had to replace my ROG phone 5 motherboard with a new one from Aliexpress due to the original shorting and completely failing. This new board is a 16 gb RAM, 512 gb storage model which I believe is an 5s board. After installing the new board and getting it successfully powered on, I see that it has it's original Android 11 firmware from 9.5.2021 As far as I can tell, it's reading as WW_18.1220.2109.126 I'm looking through the forums and am trying to update it to at least android 12 if not 13.

I'm a bit of an amateur and only understand parts of the guides and process I'm reading about that were posted back in 2021. I have a few questions and if anyone could assist that would be great:

1. As far as I can tell, my bootloader is locked. it says bootloader status unknown when I go into recovery mode and I do not get the "unlocked bootloader legal notice" that I see other's have mentioned. In order to update the firmware, do I need to unlock the bootloader? Other posts have mentioned an official Asus released bootloader unlocker and a flash tool, however as of writing, none of the official support tools from asus are available (their whole dlcdnets.asus.com repository shows up as 404). I managed to get my hands on an apk for the AsusUnlock_1.0.07_210127 that I was able to load onto the phone but have yet to use to unlock the bootloader as I want to figure out the whole precess first.

2. From the guides I've read, there are 2 main methods to update the firmware, either Flashing a Raw file or using the OTA zipped file. I have tried using the OTA zip where I downloaded the latest one from another user here on XDA that lists it as Android 13: UL-ASUS_I005_1-ASUS-33.0210.0210.221-1.1.302-2306-user.zip I threw the file in the root directory and sometimes when I restart the phone the Update Launcher on the phone detects it as an update file and attempts to apply the patch, when I click yes, it immediately goes to failed update though. From my understanding it might have failed because I need to do incremental update paths? If so, what is the correct path supposed to be from my current firmware version? I'm also not sure which OTA file serial I am currently on, as all I can find on the phone is the raw firmware file number. This thread on zentalk mentions my current firmware version and the path of updating to WW_18.0840.2111.200 > WW_18.0840.2112.210 > WW_18.0840.2201.226 working for them, but missing other key information. (Are these the raw files? from the naming schema)

2a. Is there a repository of all the OTA/raw files? like above, the official Asus repository seems to have been killed off and is now showing 404 for any links or searches for the files. The best I found was this one over at addrom with mirrored links that hopefully work: addrom

3. If I were to use the raw files instead and flash the software, how do I do so? The guides written in 2021 mention a few tools such as the asus flash tool (which when I tried to use read as the zenfone flash tool and when I tried to search for my phone to connect it, it just froze) and asus usb drivers (can't find these files). There are a posts on here that link out to other phone types and mentions flashing the firmware, however I'm getting confused by the different jargon used and cannot find the ROG phoen 5 specific tools.

4. Missing IMEI number. From what I gather, the IMEI number is crucial to get all the functionalities of the phone to work properly. I have a feeling that this motherboard was a Tencent CN model flashed with the WW rom such that it now reads as WW_18.1220.2109.126 and the IMEI is now reading as 0 (which I gather is bad). There aren't very clear guides on how I would go about fixing this, the best I found was this guide about repairing IMEI on Qualcomm snapdragon devices which have mentions of it not working well for some users. There's mentions of using a Qfil and writing a QCN to restore the phone's original IMEI which I don't quite understand, any ELI5 explanation on this would be appreciated.

If anyone has gone through the same process and have step by step instructions, I would be eternally grateful!