Computer to HD stops working

[jplot]

With the help of HP on the phone I got my win7 HD computer to send its screen image to my Panasonic 65 inch Plasma HD TV. That was about a year ago and it has worked just fine. Now suddenly it has stopped working, and no picture appears when I set the input to the HDMI 2 setting where I have always had it.
I was advised, again by HP, with this problem, to replace the cable from the computer to the TV. I did this but still no image, just a black screen.
I am fairly literate with 30 years on computers but this problem has got me stumped. I remember when I first tried to make the original hookup I got no picture, and at that time I phoned HP, and seem to remember of getting a lot of computer changes from this party from India, and his info got it working perfectly. Trouble is I simply could not follow all the things he had me do, and now I am in a fix.
Stumped in Ohio

 

[shamanxia]

Sorry, you haven't told us enough about your setup.

What model is the HP computer? Is Windows 7 on HP computer even running? Do you see anything happen when you reboot the computer and the screen is already on HDMI 2? How is everything connected? Have you updated any drivers lately?

 

[jplot]

My computer is a HP p6130y with serial number CNX921131B.--PAVILION
My HD TV is a PANASONIC TC-P658S1 (65 INCH Plasma set)

My computer is a Vista machine with win 7 running on top of that program.

This setup has worked just fine for about a year but now even with a new cable, I get nothing but a black screen.

I have no idea about drivers for this type of setup????
I have tried all kinds of simple things I can check out.
I tried using the HDMI receptacle on the TV set which ordinarily has my Roku player plugged into it, which is HDMI 1 socket, and still got a black screen. Then I tried plugging my Roku player into the #2 HDMI socket which was where I had the computer screen cable plugged into, but there the Roku player would not come up. The Roku player is run through a router box??? The computer screen signal is run with a dvi cable from the computer to the HDMI socket 2 on the TV. There is a contradiction there someplace and it leads me to believe that the #2 socket on the TV is bad. But when I plug the computer cable into the #1 socket I still get nothing but a black screen.
I am not sure where to turn, and have not found much info on this kind of setup in my searches to date.
Any advice would be apprecaited.

jvp