Long story short: my beloved Tiny TV 2 started freezing partway through any video I played - videos which have worked fine for over a year. I figured it'd been a while since I did a firmware update, so I went through the firmware update process... and now it just boots to a black screen. It's fully charged and I can see that the backlight is on, but otherwise it's totally non-responsive.

I've also put it into DFU mode (holding the Reset button + tapping Power) and I can update the firmware using the "manual update" process, but when the updater says that the Tiny TV should reboot, it briefly restarts and re-mounts the RPI-RP2 partition but otherwise is just hung on the backlit-but-black screen again.

What do I do now?