If strands are snapped quit shooting it and get it replaced immediately! A string is made up of a single strand of material (2 if two-color, etc.) so if there is a broken strand then the string is actually broken in two or more. The string is what you nock your arrow on and the cables are the ones that cross to form the "X". Possiblyit is a bad cable slide with asharp edge that is doing it but I'd get it looked at. I was wondering if at first it might have only been the end serving that is seperating/broken and then you could possibly just get it reserved but then saw you said it was at the cable slide. Anyways, get it looked at.