if you actually installed the unit correctly and it still doesn't turn. check your fuse box for any blown fuses, pretty sure you didn't disconnect the negative battery terminal as instructed as most ppl don't do this. if all your fuses are fine, check the inline fuse on the units harness. if none of those are the issue, you need to get a DMM or test light and see if the power wires you connected are receiving power. if none check out than you probably have a bad head unit.