I have a 55' TCL Roku TV and there is no sound. I have tried the reset, adjustment to audio as per instructions from others online but still no sound. My Roku TV is connected straight to the power source. Could it be the TV Speakers?
Have you tried unplugging your TV for 10-15 minutes and then plugging it back in to see if the issue is resolved?
In addition, have you tried contacting TCL support yet to inquire further? I'd suggest starting there to see what options or suggestions they can provide. Each Roku TV manufacturer provides direct support for their products running the Roku OS.