HDMI not working

[needhelpasap]

Hi

I have a HP Pavilion DV6t and a Probook 4320s, neither of which is connecting to my TV. 

My DV6T used to work, it worked like a month ago--- and now when I plug it into my Sony Bravia LED TV the TV says there is something plugged in but cannot actually detect the computer, and the computer says that it is not connected to the TV at all. 

Same with the probook. I have tried to hook it up to two different tvs, and I know the HDMI cable works. I am not sure what's going on. Any help would be really appreciated. I am going crazy over this. 

[philcosgrove]

I am having same problem with hp pvilion dv7-4177nr.  Two weeks ago it connectted to hdmi port on tv - wroked perfectly - now the hdmi tv does a data search as if it knows there is a cable attched but finds no signal.

[unobienchevere]

same problem on G62-340US, the HDMI was working perfectly but sudenly is not working anymore... any idea? I updated the Video driver, but still not working.

[Sven1983]

I am having the same problem with my dv6t (i7 2720, w mobile intel HD graphics adn Radeon HD 6770M) - used ot work, no longer does - have tried updated all drivers and software, uninstalling/reinstalling windows, I upgraded to windows 7 pro 64 (did this the first day I got it, adn the hdmi port work), when I try manually detecting a monitor, the HDMI port never comes up, it onlu asks if I want to force dual display through the vga port (which automatically connects to projector without incident) - this only started happening once I enabled switchable graphics (as the radeon card wasn't working for  awhile), though not right away. It was the strangest thing, and I'm not sure what's up.

Any thoughts would be greatly appreciated!