While making my own cat6 cables, I notice that every now and then, even though I push the cables all the way to the end that it will allow, my tester states FAIL and it shows certain wires blinking (like 1 and 8). How do I know which end is at fault and causing the fail (besides hoping I redo the correct side and, most of the time, having to redo the other side as well)? For reference, my tester is a Monoprice MCT-2690PRO.
It turns out that if you use the length option on the tester that anything with 0 in length could signal a possible wiring error. The only exception to this that I've found is if my wire is 2-3ft or less in length.