wiring ummm!?

So I installed a new stereo. I have power from the dash/battery but from there to the unit I lost power!? Checked inline fuse, good. Tried running hot from battery and still geg no power? tried to install the old unit and I get the same result! I am so lost now, my mind is boggled and I have no tunes! I get power to my amp which runs thru my fuse box but has the same in dash power supply!?