Help getting started with Roku devices, including setup, connecting your device to your TV, linking a Roku device to your account at my.roku.com/link, adding channels, subscribing to services, and more.
Per this chart all Roku units, except the first generation Roku SD (N1050) from 2009, can output at least 720p. Might it be that the Roku itself is set to display at a higher resolution that can't be displayed via composite? Without a visual display, I don't know how this could be checked or changed.
Roku Streaming Stick +, 3810X, Ser YH0059427035, wifi LivRm - Samsung UN55ES6100
Roku Streaming Stick, 3600X, Ser 5S56D8240827, wifi BedRm - JVC EM37T
Roku 3, 4200X, Ser 4124C7087583, wifi GstRm - Sanyo DP26640