Connect Roku to TV with no HDMI port

I want to Connect Roku to an old Panasonic TV with no HDMI port. The TV is 20 yrs old but works fine with my Comcast cable box. I want to stop renting the box. I bought the recommended Gana AV2HDMI converter to convert the Roku HDMI output to RCA inputs to my Panasonic. I get no picture on the Panasonic. Everything is powered up. Any suggestions?.