I have a 50 inch Panasonic model number TH50PZ77U and the HD don't work, but the digital is great. Suddenlink Cable said it was in my set and then I switched to Direct and they coyldn't get HD either and we even replaced the HDMI and moved the HD receiver to other HD TV's and they worked. Trouble seems to be in the set itself. It has always worked and then went out

SOURCE: hook up problem

change the source of the input using the remote's source button

SOURCE: Panasonic 50 inch Plasma

it could have over heated you can try to reset it first unplug it for about five minutes and try to turn it on if that dont work the remote might have a set button try holding that down until the red light flashes twice, then turn it on if not then hold the power button down on the set for a good five seconds to see if that resets it. if none of that works you will have to go to panasonic .com for the reset instructions.with the red light blinking the power supply is most likely good you just need to reset i.

SOURCE: akai lct42z6tm

I can confirm that replacing these 4 capacitors worked perfectly. I work in construction so i am not a technician or anything. I did not even have a solder iron. I have photos of the board if anyone would like to see them. Took me about a hour to replace the 4. I had to use (2)35volt & (2)50volt cause radio shack only had 2 of each and it works like a charm. This TV has been in storage for 6 months until i found this article on the problem. Cant say thanks enough!!!!!!!!!!

SOURCE: hd tv doesn't work at all says invalid format

is the tv 720 or 1080. it wont work if your inputing 1080p to 720p or 1080i

SOURCE: PS3 not working on reg tv's after HDMI use on LCD HD tv

Shelley,  the fix for this is simple! Hold down the power button for about 5 seconds and the system will beep. This resets the video setting for your ps3 from HD too whatever the current cables are that you are using too hook up too the tv. This works on my PS3 which I just bought about 3 months ago and should work with the older ones.