When you receive your Comcast cable box, you must follow the installation steps for setting up the device with your television. After the initial set up is complete, you must determine the settings that match your television settings. Using your Comcast remote, access the cable box's menu. In the menu, you choose the television type you have and you can also select the resolution that you prefer, such as 1080P.
Turn on your television and cable box. Press the "Menu" button on your Comcast remote.
Use the right arrow button on your remote to change the setting for the "TV Type" field. For example, you can set the TV ratio for 16:9.
Select the down arrow on your remote until you reach the "Y Pb Pr Ooutput" section. Press the right arrow on the remote until the "1080P" option is selected.
Press the down arrow key and make any other setting changes to meet your preferences, such as whether to have closed captions enabled or disabled.
Press the "Menu" or "Power" option on your remote to save the changes and exit the menu.