The standard doesn't allow it, that is my point. A baseline of USB2 connectivity is required for both cables and ports. A baseline of 5V@1.5A is required. Comp

The standard doesn't allow it, that is my point. A baseline of USB2 connectivity is required for both cables and ports. A baseline of 5V@1.5A is required. Compliant (USB) devices are required to come up and enumerate even if they can't get the power contract they want or the speed that they want. It is on the software to convey to the user that something the device needs is missing, the USB spec can't really speak to that, but there is not any situation allowed in the spec where you connect a USB device to a USB host and there is no working data&power interface at the end. > BTW., as an update - I just received "USB 3.1 Gen 2" cable. It doesn't work. It sounds like one of your devices is broken.