Stereo problems w/ 2004 Tahoe

I installed a new Amp in my wifes Tahoe but in the process i took her stock 6 disk CD player out, when i plugged it back in the stereo works fine but it now states "no disk" and it won't play or eject any of the disks i know are in there.  Is there something that needs to be reset or how can i get this back to playing CD's or did i fry her stereo...Thanks

i doubt that u fried it. it might need to be reprogrammed for the VIN relearn but u need a tech 2 either way