Phantom power won't work on certain xlr cables. Why?

I think that certain xlr cables won't run phantom power. Why would that be? Although, I haven't experienced it myself. People explain to me not to use certain cables with a certain mic because the cable won't run phantom power. I have a bunch of cables that have been rejected and this is one of the reasons explained to me when they come out perfectly fine with a cable tester. All three pins test fine. So what would be a reason why an xlr cable won't do phantom power????