how to verify that my neo-geo AES is jap ?

hello to all

Before my aes i had an CDZ system and could verify that the game system was japanese by going in the memory menu but i want to verify that this system is well japanese and not us...how could i do ? i have two games with it : snk chaos and soccer brawl

Insert a game, turn it on, if its in English its US, if its in Japanese its JPN.

well soccerbrawl have menu in english but the first thing i see is a word saying this game is for japanese country...