Help with toning phone/data lines

I have been assigned the task of toning/tracing a bunch of phone and data lines for the company I work for. I have never done this before, but it seems fairly easy. Until now. Suddenly, I’m getting no signal on the data lines. I know these lines are active (we just moved a bunch of PCs from that location). Nobody has changed anything since the move. I’m still getting voice tone but not on data. I’m using a Paladin Tools 1573 with an RJ-11 phone cord to trace the lines. Any help would be greatly appreciated.