You have installed your Gigabyte Titan Ridge Thunderbolt card but you can't get it to work. No problem! With the right BIOS settings, you will! First, let's take a look at the errors: Thunderbolt Controller 15EB This device can not start. Code 10 STATUS_DEVICXE_POWER_FAILURE PCI Express Downstream Switch Port This device is not working properly because Windows cannot load the drivers required for this device. The Fix: For our Prime Z390-A motherboard, the fix was easy. Go into BIOS Advanced Thunderbolt Configuration Discrete Thunderbolt Configuration > Enabled DTBT Controller 0 Configuration DTBT Controller 0 > Enabled DTBT Controller 1 Configuration DTBT Controller 1 > Enabled Enabling both DTBT controllers solved the problem!