I just got a new Panasonic TV. I believe it's the plasma ST40 version. Anyway, when I went to plug my PS3 into it, the PS3 recognized that it had an HDMI in it so it asked if I wanted it to change video settings. I accepted. I then updated the PS3 to the latest firmware. I then plugged in a game disc, it loaded up and I got a bunch of grey static. I then loaded a Blu-Ray disc in and then the TV lost the connection and said that it couldn't find an input. I then tried running a DVD on it and THAT actually worked.
I know it's not a disc drive issue because I then tried running everything through a composite cable in SD and it all worked just fine. I feel really helpless here since I don't know what the problem is; therefore, I cannot fix it.
Did you test your HDMI cable with another device to make sure that it isn't the problem? Did you test the HDMI port on the TV with another device to make sure that it is correctly set up? If you haven't used your PS3 with HDMI before, then there could be a problem with the PS3 HDMI port; but it is more likely to be the cable, or the new TV.
I have two HDMI cables. Both of which I have used on the HD cable box. Both have worked on it without a problem. The PS3 works just fine on the XMB menu, just not when running games or BR discs. It also works just fine with downloaded content, both PS1 classic games and downloaded PS3 games.