Could you tell us more? For example, are you using an old model Roku, or are you using a recent roku with some conversion device? Can you list all the device models in use? And could you describe “sync”? ie: are you seeing a picture but the horizontal or vertical hold is not locked on, or something else?
It is a 2006 Zenith Model RM-20LA70 Rev A, and a new ROKU Express device. I connected (from Amazon) a “Dingsun HDMI to RCA Converter HDMI to AV Adapter HDMI to Older TV”
https://www.amazon.com/gp/product/B07GRXDZCF/ref=ppx_od_dt_b_asin_title_s00?ie=UTF8&psc=1
The tv is just static
Here is the user manual for your TV.
https://cdn4.all-guidesbox.com/download/054a21d1e6389263d96585bccc1e8abd.html
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Refer to pages 12-15. Basically, says to press the tv/video button on the remote to select the appropriate input (component). If you are getting static, you are likely on the antenna input. You will need to cycle through the inputs using the tv/video button on the Zenith tv remote until you see the Roku Home Screen. (or, if the Roku is not yet setup, you will see the Roku Welcome Screen).
It is a Cisco remote with no “source” capability
From page 6 of that manual, there should be a physical TV/Video button on right side of TV (2nd from bottom) that will allow you to toggle between inputs.
You may need to restart the Roku again in order for it to appear.
