Hi @Anonymous User
I am guessing you have tried your NowTV Stick or Box on a different HDMI port on your Toshiba television ?
If you are using a box rather than a stick try a different HDMI cable has well.
Should you be using an external HDMI switch box, then bypass it and plug your Stick or Box directly into the television.
Also go into the Settings on your NowTV device and under Audio settings play around with the different sound options (start with Stereo) to see if you can get any sound.
Other than that play around with your Sound and CEC HDMI settings in your Toshiba menu.
