Hello I am new to this forum. I just had he comcast hd/dvr box installed a few days ago. Well today my hdmi cable arrived from monoprice so when i attached the box to the tv via the hdmi cable all the non high-def channels are displayed with the black lines on the side 4:3 is there anyway to correct this...

Turn the box off, press menu.

Enable 4:3 override set to 480i. Also make sure the HD output is set to 720p or 1080i, as most appropriate for your display and/or preferred channels.

thanks