Usually, if you can't hear any sound from your bow, it's because:
1. Your strings are coated. (Such as Elixir etc.) As explained on our website, coated strings are not suitable, unfortunately.
Because the bow can't get enough grip on the strings, to check if your strings are coated, enter the brand model on www.sweetwater.com and check it on the specs chart.
2. You need to apply more rosin to the bow; please repeat the steps on the user guide, Minute 0:17
3. The bow hair has soaked some of the natural oil from your hands and prevents the rosin from sticking to it. Take a paper towel and some pure alcohol and clean the bow hair with it. Let it dry and then apply the rosin again.