Yes! We do test all cables that we build before shipping them to our wonderful customers!  They are checked both visually and with a PSU Tester to ensure proper function!Additionally, all modern power supplies include built-in fault protection, which turns the unit off immediately if a faulty cable is inserted. The PSU has a relay click when turning on, but if fault protection is triggered, you will hear it click again immediately indicating that it has shut off.In short, even if a cable passes our inspection and test, but is then damaged in transit or is subject to some other freak accident, there is still no risk of damaging any component with an incorrect or faulty cable! (yay!)