This is a fairly common problem that is usually a quick fix.
1) Make sure that speakers are powered on and that the volume on them is all the way up.
2) Make sure that the volume is all the way up on your computer. Look to the bottom right corner of your monitor. There should be a little speaker icon in the tray at the bottom. Clicking on this icon will bring up the volume controls. Make sure that the volume is all the way to 100 and then test it. If it is still not working you may need to change where the sound output is.
3) Remember that little speaker icon from step 2? Go ahead and click on it again. In the menu that comes up, you should see something along the top of it that is saying where the sound output is. Mine says speakers/headphones. This will be different depending on what you are connected to. If you have more than one audio output available, there will be an arrow here that you can click on and choose what you want the output to be. Changing this will usually fix the sound issue. If it does not, some more steps may need to be taken. Send in a ticket, and I will be on it ASAP.