Prime bricked after firmware upgrade ?

[meridian]

Hi all,

I have a problem with my Prime since I tried to upgrade his firmware with the Connectivity Kit.

I clicked on update button and the update dialog box was displayed.
After few minutes, this dialog box disappeared and the calculator displayed nothing.
I tried to power on without success. Press reset only displayed a black screen.
I tried all key combination that I found. Only [Symb] + reset display the following message :
CodeEntry:0xaa55aa55
HP Prime recovery mode V16.

Now the Connectivity Kit doesn't find the calculator.

Could you help me to unbrick my Prime ?