UE46D5500 the most strange problem!!

[yannis76]

Hi,

I have been using my HTPC (Intel, GTX670) for several months with UE46D5500 TV. One day I decided to take out the GTX 670 from the HTPC and try it on another PC. Since then I can not use it back to my HTPC!!
When I install it back to the HTPC and connect it to TV through HDMI I get the "No signal" message. I have tried the following:
1) test the GTX 670 in another PC/monitor and works fine
2) test the whole HTPC in another monitor and works fine
3) test another PC to my AV receiver/TV combination and works fine
4) tried several HDMI cables and power plugs (!!) but no difference

Any more ideas??