I don't know if there is a service mode like that, maybe there is. However, my PCM-M10, bought in Germany, has a language selection in the detail menu, giving a choice between English, French, German, Italian, Spanish, and Polish - and not Japanese. If yours is Japanese and does not give you a language selection, then this could be a sign that the Japanese model uses a different firmware. If they used the same, Japanese would likely be in the language selection among the others. As far as I know, Sony regularly does this with their mp3-players, where Japanese versions "speak" only Japanese.