A:Answer Thank you for your inquiry! To ensure your Insignia™ 24" Class F20 Series LED Full HD Smart Fire TV starts on the HDMI input where your Comcast Cable box is connected every time you power it on, you'll need to adjust the default input settings. Begin by accessing the Settings menu from the Fire TV home screen. Scroll to the top and select "Settings" (the gear icon), then navigate to "Display & Sounds." Within this menu, locate the "Power On" settings. Here, you'll find the option for "Default TV Input." Select this option and choose the HDMI input that corresponds to your Comcast Cable box. After making your selection, exit the Settings menu to save your changes. Test the setup by powering off your TV and then turning it back on to verify that it starts on the HDMI input you selected. If you encounter any issues or if the settings differ from those described, consult the user manual for your specific TV model or contact Insignia customer. Keith | Insignia Support https://www.bestbuy.com/site/insignia-24-class-f20-series-led-full-hd-smart-fire-tv/6490138.p?skuId=6490138support for further assistance.