Kindle 7th gen bricked

Hello. I have a kindle 7th gen WP63GW and one day the battery went 0% and is now dead. I tried all kind of things to revive then and nothing.
So i opnened and in battery i have 4.1V so I don't think it is "only" battery related.

Tried to use the serial port and all the time i have this error:

[ 58.243573] mmc0: Timeout, intmask=0x00100000
[ 58.248967] mmcblk0: r/w command failed, status = 0x80900
[ 58.254983] end_request: I/O error, dev mmcblk0, sector 1118259
[ 63.685513] mmc0: Timeout, intmask=0x00100000
[ 63.692958] mmcblk0: error -110 transferring data, sector 1118256, nr 8, cmd response 0x900, card status 0x80b00

So, any help here please