Unsolved Recalbox not booting (Pi4 / NesPi Case)

[pignouf3]

Hi,
Here is my current config :
Raspberry Pi: Pi4
Recalbox version (build) : 9.2.2
Matériels (Micro SD, Power Supply, etc.): NesPi Case, System & games on a micro SD 64Gb

My recalbox was working perfectly well running on recalbox 8 something until I updated it to Recalbox 9. Since then, it seems it is not booting.

I tried to boot many times and nothing was happening, no picture on the screen nor sound and when I was turning it off through the power button of the case, it was never switching off, I had to unplug it so it was finally shutting down.
I left it like that for quite some months and tried to get back at it this week.

After a few different tries I am coming at you as I don't seems to find any resolution to this issue.
Here's what I did :
-I tried to connect to the recalbox through my PC but was not seing it (and had no access to the interface to get the IP)

• I tried to switch to another HDMI port on my TV
• I took out the SD card and plugged it in my PC and everything seemed fine in the folders
• I run the manuel update procedure putting the latest version on the SD card and pluggin it back, the update seemed to have worked as there was nothing left in the update folder of the card. Still nothing so
• I formatted the card back with a fresh new install of Recalbox via the Raspberry imager (deleting all my games and stuff)
• Plugged it back but on a computer screen and after a few minutes I finally have a picture : the 4 ghosts splashscreen but it stays stucked there and nothing happens when I tried to turn it off through the power switch
• Tried to remove the SD card and it turned on saying there's no SD card in and turned off properly

Here's where I am. Any idea of what I should do ?

Thanks so much for you help,
Pierrot