My computer won't play sound!?

Okay, so, I was watching a YuTube video, but then I had to, um, do some 'duties'. When I got up and started to move, my foot got caught under the cord for the headphones I was using. My foot got caught, and before I could do anything, my foot pulled the CPU down, which landed on the carpeted ground, the computer went to a blue screen. It then shut down and restarted. Now though, sound won't play at all. All functions of the computer work excpet for sound. The Headphones won't play sound. Thinking it was that were broke now, I tried different headphones, but these also didn't work. All computer volumes have been turned up the highest they will. But nothing plays sound.