stereo vs. ignition

I pulled my stereo out to try to fix my jammed cd player. Once I put it back in, my car won't start. I turn the key everything comes on but the ignition does not engage, doesn't even try to turn over. I have removed my negative battery cable and put it back on and it still will not start. The display on my stereo does not work as well (it was already brokken as well) so I don't know if I'm missing an error message. I have also replaced the fuse on the iginiton sensor as well to no avail.