Black Screen of Death

I started playing my 3DS again yesterday after not touching it for a while, and after booting it back up this morning, I found that it was stuck on a black screen with the normal theme music playing.

I can't figure out why it's not showing anything on the screen, and while I've looked up multiple "Black Screen of Death" fixes, none of them so far have worked.

What I've tried:

• Rebooting the system.
• Removing the battery and putting it back in.
• Booting the system without the SD card - it still shows a black screen even with the SD card fully removed.
• Performing a system update in Recovery Mode with Up + A + L + R while booting up. Weirdly enough, when forcing a system update this way, the screen does display during the update, but it still won't display when turning on normally. So clearly, this isn't a hardware issue.

At this point I've no more ideas left. Normally I would call Nintendo and try to schedule a repair, but due to the pandemic they're not currently taking any repair orders. Any ideas?