I have a 2006 Infiniti FX35. Change the battery, still can't get the Stereo/video system to opera?

I purchase a new battery from Firestone. Installed it in my car 2 days ago. The car started right up. Then I remembered turning off the stereo system before disconnecting the battery. But when I pushed the on/off on nothing happened. Checked all the fuses, reconnected the battery, still nothing.