Abstract: Various embodiments include techniques for detecting a poor-quality cable associated with a wired communications channel that is causing noise that interferes with a wireless communications channel. The techniques are directed towards a test that a processor performs when the cable is installed in a user system. A wireless test application, executing on one or more processors of the system, determines a noise floor for the wireless communications channel when the wired communications channel is disabled. The wireless test application determines the noise power for the wireless communications channel when the wired communications channel is enabled, thereby causing interference in the wireless communications channel. The wireless test application compares the noise power to the noise floor in order to determine whether the cable is a high-quality cable or a low-quality cable.