Review on 2-Pack - DIRECTV Broadband Deca Ethernet to Coax Adapter - 3rd Gen (with 2 USB Power Cables) by Steve Lawrence

As others have said, USB power only works from any device that is a true USB host. also known as a type of computing device. I will never understand why this is so. Most people should get away with just buying the included power supply kit. If you really need USB power to work, take a look. I installed one of these under the ceiling and didn't want to tuck in another bulky PSU for no reason. It turns out that the Raspberry Pi is a very compact way to power the USB for these DECA adapters (since it's a real and very small computer with USB ports). It's not cost effective, but sometimes it has to work a certain way. Here's how you can do it. Second, try different micro USB cables, not just the ones that come with the kit. The bundled charging cables are tricky, and I've found that other cables work while the bundled ones don't. It's ridiculous value when you run them. These are very stable and compact devices. It's not the top choice for home wiring, but if you have no other choice, it can be great.