I have a roku RCA TV and it constantly makes a loud ringing noise. The Tv is only about a year old. It started only happening when the tv was turned off so i would just unplug it from the wall but now the noise is there when i am watching tv also. I have tried factory reset, playing through theater speakers, turning off WIFI and nothing seems to work
A number of TV manufacturers license Roku technology for inclusion in some set models and market them as "Roku TVs". Roku doesn't manufacture "Roku TV" sets, it only supplies the Roku operating system.
This sounds to me like a hardware issue that needs to be referred to the manufacturer of the set.
Manufacturer support contacts for RCA:
https://www.rca.com/support-products
https://www.rca.com/us_en/television-4-us-en/customer-support-396-us-en
1-800-968-9853