Aura H2O Dead KOBO ?

Hey guys, i'm heading on this forum after reading multiples good reviews about you. Yesterday, I found my old Kobo H2O lying around in some boxes. I think i never powered her for like 8 years or more.
But i thought that would be cool to use it, i do prefer paper books but mobile reader is always good to have.

So i tried to plug it in a wall and it was saying "Restoring" the square were moving and after maybe 10 minutes, a screen appeared with a computer (i think it ask me to connect the reader to my computer...) so i connected it and it asked me for a validation, i said yes and then back to the restoring loop.

I read several methods on forum and on kobo official website, what i have tried so far :

- Plug the kobo for like 2 hours on a wall charger
- When it try to power her without cable connected, the led doesn't light and the restoring process is frozen.
- if i connect it to my computer and try to start kobo desktop : it is doesn't recognized.
- I tried the factory reset several times without success and even tried to tap on both bottom corners of the reader : no success either.

What I Know so far : if connect it the led lights in blue if reader isn't connected to a powersource : nothing happens

For me it might be the battery that is dead, but if someone has an advice to give, i'm open and willing to try

Thanks to everyone :2thumbsup