Sounds like a boot-loop rather than a hard brick, so hold on: there is hope!
First thing to try would be to see if you can boot in recovery and/or fastboot mode:
1. Turn device off (and make sure it's fully charged, but from your post I understand that you did that already – although I'm not completely sure it actually charges if it is off).
2. Press and hold
simultaneously Power + Next buttons (for fastboot) or Power + Back buttons (for recovery) until something happen; the LED should be purple (red + blue).
3. Try both and report the results here. In the meantime, you can go and read
https://wiki.mobileread.com/wiki/Boox...roubleshooting (it's actually for the M96, but the firmwares are quite similar).