i bricked my phone after relocking bootloader with a custom rom ( no boot/recovery/fastboot… yep i’m a genius ) anyway i saw that @rhunault succeed resolve the probleme here
so if someone know how to solve the problem ,please tell me.
I already tried to flash this rom : gs290_10.zip but it doesn’t because its not signed, so it failed
OK dumb me is back, so as i get negative answer from gigaset, for my problem. i deeply believe that my new phone became a paper weight, i said well lets try random thing ( thats dumb me talking here, hold on) so lets try to flash all files that doest ask for signature long story short it work !
so i share for every one who’s got a bricked phone just uncheck all file whot need to be signed like logo, well try it. this phone is awesome !