Well, after ~10 minutes, and still a black screen, I started some furious attempts at CPR by pressing the power button, sometimes holding it, sometimes pressing it quickly, basically anything I could think of, and nothing was happening. Eventually, I went through a few minutes where the red power led on the tablet was blinking about once per second, and by holding the power button, I could switch it off. Again, more furious mashing of the buttons, lots of sweating, and finally about 30 minutes after the original reboot, I saw the Chuwi logo flash on. That happened a few times like the screen was glitching, but eventually, I got to the Android/Windows boot menu, and was able to boot. I don’t think this is normal–simply changing the memory speeds in BIOS should not result in a 10+ minute reboot, but at least the tablet finally came back to life.
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