(TL;DR and update at the bottom)

Running a rooted (Magisk Delta) LineageOS 21 (ver. from 27 Sep) on a Motorola Edge 30 (dubai).

Managed to brick it by simply activating the "Invert colours" option in the settings. After doing so the screen has turned off and is unresponsive. Bootloader and recovery work fine. Booting into the actual OS shows the lock screen for a split second before the invert module activates and turns the screen off again.

Even though the touchscreen is unresponsive, the physical buttons/functions still work just fine (long pressing POWER toggles the flashlight as per my settings, and shaking the phone also toggled the flashlight before I rebooted the system). Upon connecting the phone to my laptop via USB, it shows up in lsusb, but of course doesn't mount itself since I'd have to open the USB connection settings window in the phone to mount it.

I did some digging and it turns out that this is a relatively common issue. My first instinct was to just go into recovery, connect via ADB and modify the settings file via adb push or adb shell settings, but my laptop is not authorised, so I can't do anything with ADB on it. Trying to authorize the laptop without the screen seems impossible. This, this, and this post, among many others, didn't work. Anything related to ADB might very well be out of the question, because even though adbd is running as root I still don't have access to any important parts of the file system without authorization (for reference, the /data, /sdcard, /mnt/system/sdcard, and /system directories, among many others, are empty). Editing prop.default or default.prop ADB properties to enable insecure ADB also doesn't work as upon rebooting the properties return to their initial state.

Screen duplication and remote input programs like scrcpy also don't work as they require ADB authorization to perform inputs.

I tried booting TWRP, but I couldn't find an image that could boot on the phone. Some got stuck on the boot logo, while some bootlooped ad infinitum.

I'd really like to repair this phone ASAP, as quite a few things depend on it and I was stupid enough not to make a proper backup, with my only one being my old phone containing data up to early September that I haven't wiped yet.

If I won't be able to do anything this week, I might be able to do something on the weekend when I get back home and hopefully use adb via my main PC, which should still hopefully be authorized. If it's not, I could try plugging an external display into the phone and/or a keyboard/mouse in order to authorize ADB.

I know posting this on Lemmy is a bit stupid considering how small the communities here are, but I figured it'd be worth a shot. If this doesn't work out I'll post it on XDA or StackExchange

TL;DR:

• Turning on "Invert colors" option in LineageOS 21 for the Motorola Edge 30 (dubai) turns the screen off and makes the touchscreen unresponsive while the phone is in the OS. Bootloader and recovery work fine.
• My laptop is not authorized to use ADB, and as such, I cannot access the file system to modify settings and/or recover data via ADB
• TWRP is not an option as there doesn't seem to be a valid image for my device
• Screen duplicating programs (ones that I know of at least) cannot work without ADB authorization
• I might be able to authorize the ADB connection by plugging an external monitor and mouse/keyboard into the phone when I get back home

I'm looking for a way to either revert "Invert colors" entirely or at least recover data from the device before I wipe it.

In order to do that I would have to:

• find a compatible TWRP image, OR
• bypass ADB authorization/enable insecure ADB, OR
• plug in an external input device and hope that it works (a keyboard would be the best bet)

Any advice is very appreciated

Update, 12 Oct 2024:

Unfortunately the ADB authorization on my main PC expired, and the phone didn't support video out via raw USB to HDMI, so I had to just wipe it. Thankfully at least I didn't lose everything because of my old phone that I haven't wiped yet, but still.

I did some testing after I wiped the phone and it turns out that the touchscreen is functional, it's just extremely hard to get any signs of life when you can't see fuckall. Likewise, the screen isn't completely turned off, just EXTREMELY darkened. At full brightness the bright blue header of the setup notification was visible with the setting turned on, which was enough to let me navigate back to the setting without much hassle.

If you're having the same problem, then genuinely try to feel your way back to the setting, this will be even easier if you happen to have a second phone with LineageOS (or any modern Android, really) on you that you can use as a reference. And of course make backups regularly unlike my silly ass. In fact, go do one right now. Just do it. You might thank yourself later. I know I would have.