Audio not working on iPod Touch 4th Gen after Display Replacement?

I replaced a broken display on my iPod, but after turning it on, it won't make a sound, when i select a song to play it will bring to the now playing screen and "play" it for like 1 second before it pauses the song. The song itself will not move on the time line bar(where it tells how far into the song you are). When i select different alarms it freezes for like a second. I've also tried games that should have sound they work but don't emit any sound. What do I have to replace? What might have caused this?

thanks in advance for any help given