One you can run HDMI to 100 ft with out trouble, anything over that you need a booster.
Did you get a new tv & is it bigger?
The bigger the tv the more you see "problems" in content, like pixilation & banding.
What model tv & brand is it?
Could also be some tv setting(s) ON that should be OFF, like noise reduction should be low or off, high normally adds problems. What mode is the tv in?
Cable has never had best PQ. What cable company do you have? & what model cable box do you have? Some models are better then others.
Good places for good cables at very good prices:
I have a cable box that is remotely located on other side of room (approx 40') from TV.I ran an HDMI cable through wall/ceiling. I get a lot of pixilation and disruption of picture. Cable guy says there is plenty of signal strength at cable box. Any suggestions? Cable guy says any run over 30' requires a heavy duty HDMI cable. Is this true and where can I purchase one? I have a HDMI cable that was purchased on ebay as locally they are ridiculous $.