One great change with the 3rd-gen Fire TV Cube, compared to both previous models, is the inclusion of a full-sized USB-A port whereas the old models used a micro USB port. This eliminates the need to use an OTG cable for connecting the vast majority of USB drives and peripherals. The other change Amazon has done with the new Cube’s USB port, which is unlike the past models, is cutting off all power to the port when the Fire TV Cube goes to sleep, whereas the older Cube models kept the port powered all the time. This change can be beneficial to some for automatically turning off external devices when the Fire TV Cube isn’t being used, but it’s proving to be an annoyance for others, such as those using external Gigabit Ethernet adapters for additional wired network speed.
A software update for the 3rd-gen Fire TV Cube has changed it so that the USB port now remains powered while the device is asleep.
Amazon has always used a 100 Mbps Ethernet port on all of its own external Fire TV network adapters and all Fire TV models with built-in Ethernet ports. The new Fire TV Cube is, unfortunately, no exception and also uses a 100 Mbps Ethernet port instead of being upgraded to a Gigabit Ethernet port. While 100 Mbps is fast enough for the absolute best video quality offered by any streaming service, which is likely why Amazon felt there was no need to upgrade it to a Gigabit connection, it’s occasionally not fast enough for a small subset of users that push high bitrate local video files to their Fire TV, such as uncompressed Blu-ray rips. For those with internet speeds greater than 100 Mbps, it’s also just nice being able to fully utilize that connection for general Fire TV downloads, like app installs, OS updates, image downloads, and more.
While WiFi speeds on Fire TVs have long exceeded 100 Mbps, some people prefer the reliability of a wired Ethernet connection so they choose the slower connection option instead. A middle-ground solution has always been to use a third-party external USB Gigabit Ethernet adapter with Fire TVs. With an external Gigabit Ethernet adapter, you still won’t be able to achieve Gigabit speeds, due to the USB 2.0 connection limiting you to 480 Mbps which translates to around 300 Mbps in real-world use.
Since the Fire TV Cube 3 cuts power to its USB port while sleeping, it means the Cube will have no network connection while asleep if you rely on an external ethernet adapter of any kind. This results in the Cube’s light bar strobing orange all the time and prevents all Alexa commands from working until the Cube is woken up manually using the remote. The USB port loses power whether you have the Cube set to output no video or a black screen while sleeping. However, all hope isn’t lost for those wanting a faster wired connection without any annoyances.
The solution is to be sure to configure a WiFi connection in addition to the external Ethernet connection. This way the Fire TV Cube falls back on its WiFi connection when it loses its external Ethernet connection while asleep. This prevents the orange strobing bar and keeps Alexa working while asleep, but allows you to use the external Ethernet connection while the Cube is awake. You may occasionally notice the network connection flipping from WiFi to Ethernet if you’re quick to use the Cube immediately after it wakes up, but it shouldn’t be too big of an issue.
While having a fallback WiFi connection solves the external Ethernet issue pretty well, the USB port powering off can still be annoying in other situations. If you like using a USB keyboard to control your Fire TV Cube, like the popular Logitech K400 or K600 which are made for TV devices specifically, having the USB port power off means you won’t be able to wake the Fire TV up using the keyboard. I’m sure there are other scenarios where a dead USB port during sleep can be a nuisance. With any luck, Amazon will add an option in the Fire TV settings to toggle the USB port on or off while the device is asleep. In the meantime, be aware of this USB behavior change if you’re a heavy user of the Fire TV Cube’s USB port.