Hey thanks @Chyro, in fact I bough this keyboard after seeing your Fk-555 video! I'm a huge fan, love your channel!
Here pictures of the back panel, in metal... That sound like a fk555... But no model number... So I decided to open it...
Here what a found on the PCB: FK-B007... Already tested one of these??
Thanks again, and hello from Quebec City, Canada!