PS3 controller won't sync

So I realized my first controller wasn't turning on or charging. I went to a nearby game store and bought a used one. I tried to sync it to my PS3. I used my USB cord to try to sync it but it had no effect it wouldn't blink (how it blinks when it is charging) but nothing. When I press the home button it blinks, so I don't think there's a problem with the controller. I thought it could've been the cord but it wasn't. I connected the cord to my mic and it charged. I tried pressing the reset button on the back but it still wouldn't sync. Any suggestions?