I have an old Akai plasma. My oldest Roku box stopped supporting Hulu last year and just stopped supporting Netflix last month. I have a newer box, but it has the av AND the hdmi connector. Av was connected to the "in" for the old box, do I plug new boxes av there and get the convertor to plug thechdmi into the dvi u mentioned u had on ur Sony? I'm confused
So, you have an old tv without hdmi input, yes you will need a converter, not just plug or cable converter they don't work. You need a box with circuitry to properly convert from one signal to two. Like this one:
Dvi is only video, you need a separate audio line which the above converter gives you.
As for your newer Roku that replaced your old Roku, it still has av outputs? That makes it at least 5 or 6 years old, its channels are going to stop working soon too, I would upgrade to newest Roku you can, so you get ALL channels going forward. All the Roku needs is hdmi output, which links to hdmi input on the converter, the video is sent to tv by dvi, and the audio by breakout cable 3.5mm to rca.