This sometimes works. Unplug all connections from the TV and then unplug the AC power from the TV then leave it for a hour. Come back and plug in the AC then a single HDMI on port 1 and re-test. No guarantees but a few folk have reported success so we always try it.
It is an LG LCD TV Model 52lb5d
We have had trouble with our tv for a while now. When we turn on the tv, a screen saver will come up with either 'no input' or 'invalid format'. After a while the picture and audio flickers, sounding like something from Star Wars. The time it takes for the picture to fully kick in has increased to several hours. Now we have to leave the tv on ALL the time for fear that it wil not come back on at all.
We have a HD Direct TV box, Samsung Blu-ray Player and an Xbox 360 hooked up to the three different HDMI ports. It does this on all ports, on all devices. I have tried switching the devices around to different ports, tried each one in all three ports, same result. The Blu-ray does not work at all, and it was the first device we noticed it on. The Xbox works the best. I have tried a new HDMI cable with all devices and ports as well, no good. I have switched inputs, unplugged everything, even from the wall, no result. The HDMI ports seem to be the only issue, AV and USB works fine.
It is most likely a main board issue that will have to be replaced, but I thought that I would try a forum to see if anyone has any other suggestions. Thank you.