[Q] Help with bricked tab topic

I have spent all night researching this forum, and have had no luck finding a solution to my problem. My tablet is stuck at either the lock screen (15% battery, no touch controls) or "shutting down" loop, all depending on how I power it up. Most of the methods listed on the forum either involve flashing updates via SD card (none have worked so far) or require me to load a bootloader via PC connection (which I cannot do since I cannot access tablet settings). Does anyone know how I can get this thing working again? I assume that an OTA update was mishandled by the previous owner, and this is the cause of the brick. Any help would be greatly appreciated.
Thanks in advance!