nope I think thats the problem, but I don't know how to boot up in this mode :-(
btw my L button is broken (I already orderd a new one ...) but It will come from china ... :-/
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if I restart my system rxTools is not booting ... I don't know why ... all the time ne normal sysnand is booting :-/
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I guess I got it. I started the browser up and opened the rxtool website (section 2) and it worked for me.

thanks for your help!