Finally got my 990 and 770 plugged in and configed.

However, I am not getting any sound out of the center speaker. The two fronts and sub are working. I haven't hooked up the rear surrounds yet. Ran the auto config and then manually tested. Replaced speaker wire cable and cable from 990 to 770. Plugged the speaker back into the old amp and it worked.

Am I missing something paingfully obvious?