Finding Damaged Section of a wire in a wall

Well in theory… BUT, this particular run is routed against a brick wall. It’s hard to explain, but the drywall only goes up about 3 ft of the wall. All of the data, phone, and electric is run along the top of this short wall and dropped down between the furring strips accordingly (they’re vertical). Along the top of the wall is a fancy sill that makes a box around all of the cabling. Not to mention that the entire place is freshly drywalled and painted. If I have to tear out new walls, I want to make the repair job as small as possible and repair the cable.

The owner doesn’t seem to care too much. These will be under a desk that will be built into the wall. I mentioned as an alternative to just use the next jack over (about 10 ft) and permanently mount a switch/hub under the desk and give him a few more ports right there.