Flicker on HD CRT

Within the last month my HD CRT tv has been flickering. It use to have an awesome picture, better that some of my friends with newer HDTV's to a washed out image. The flicker is pretty sporadic and it is almost like it may be some kind of electrical interferance, however I am no expert. If somebody could clue me in to a way to solve this problem I would appreciate it greatly. I can't have any of my friends over to watch anything because I feel embarrased about how bad the picture looks sometimes. Thanks in advanced for anyone who helps me.

double check all connections, you do not mention if it is only a video in or is it off air too? then if that is of no help, you can get a filter that will eliminate EMI interference. and check the ground to either cable or sat. this will cause issues. a broken/frayed wire will also cause it. make sure you cables are good quality. not out of box issue.

I get the flicker while watching cable which is run into a component video input as well as the HDMI input which is hooked up to a Blu-Ray palyer.

I think I fixed it. I took everything apart, dusted everything off and it seems to have gone away!!! About to watch the Dark Knight without the flicker!!