Re: Fuse help!
Is the radio the only thing that is not turning on?
(Usually) there is a fuse for the radio itself on the back, though I haven't had the head unit out for a while to say this with certainty.
Either way, it is seldom on a separate circuit, so if you have blown a fuse higher up, there should be some other systems that aren't working properly in addition to the radio not turning on (Aux. power through the cig lighters would be a good place to start).
If you find any other systems that don't have power, you know what circuit the radio is on, and which fuse to replace.
If you are sure it is only the radio, I would look for a fuse in the head unit itself.