So you don't have a roku tv, you have tv and you want to power a stand alone roku via usb cable, is that right? You posted in the Roku tv section, these are actual tv with screens and have roku built-in. What is the name and model number of the roku? If its a Roku stick+, you shouldn't power them from the usb port of the tv, you should plug it into a wall outlet.
It’s actually the Roku plus and it’s the USB cord that plugs into the wall and the back of the Roku device. This is my first time in this community chat LOL
There is no "Roku plus". There are a couple versions of the "Express +" (none in current line), a couple versions of the "Premier +" (one in current line), and a "Streaming Stick +" (in current line).
Both Express + and the current Premiere + use the Roku® Micro USB Power Adaptor — PW10, available here: https://www.roku.com/products/accessories/streaming-stick. This is just a standard USB micro to USB A cable and a conventional USB power adapter to plug into the wall. Another cable and adapter you may have handy will do as long as the adapter has a rated output (read the fine print on the adapter) of at least 1.0 amp, or 1000 ma.
The Streaming Stick + has its wifi receiver built into a special USB power cord, so if you need it, it will have to come from Roku (USB Power Cable with Long-range Wireless Receiver, on that same page). For power they sell the Roku® Power Adaptor with Extender Cable — PW10 on the same page. Again you could use another 1 amp power adapter you might have on hand. The included cord is a USB A male to female extension cable you can use if the cable with wifi receiver usn't long enough to reach your outlet - you might be able to find this locally.
The former Premiere + (model 4630) had a 1 piece adapter with a permanently attached cord. The cord plugs into a round connecter on the Roku 4630 instead of a USB jack. I can't find this adaptor on the Roku site, but there are 3rd party ones on Amazon - be sure it's compatible with Roku model 4630.
Roku Streaming Stick +, 3810X, Ser YH0059427035, wifi - Samsung UN55ES6100
Roku Streaming Stick, 3600X, Ser 5S56D8240827, wifi - JVC EM37T