I connect it with the dock cable but my computer does not recognize it. I've tried everything.
Impossible to answer with information provided.
What kind of computer do you have?
What version of the operating system is it running?
What version of iTunes is installed?
If you have truly tried "everything" then there is no hope that it will ever work again. On the off chance that you didn't try "everything" tell us what you did try, and perhaps someone can see something that you missed.
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