If I read your post correctly, what you are saying is that the 'flashing' process didn't actually get past the first stage? I'm afraid the only suggestion I can make there is to try again with a freshly formatted CF card and freshly downloaded files. There is a step by step guide, in the pinned thread about cacko, on the Sharp rom forum. You might also find some useful help on the Tyrannozaurus site.
As regards the unusable Japanese rom: I presume your 3100 is working, but only in Japanese? If you go to Trisoft.de, as suggested in another post you will find a backup of their 'englished' rom. You can follow their instructions from their site, in the pdf of their manual, and get back to a working english rom.
You'll then be in a position to try again. Good luck.