I hooked up my Studio 1737 to the TV via an HDMI cable and it worked perfectly. However, after about 4 uses, when I began a video, there was no sound. Then, the next time, no signal at all. I have tried re-connecting, re-booting, etc, but now all I get is a "no signal" message from the TV. Any ideas what may have gone wrong?

What OS? Vista?

Right click on desktop and choose, 'Personalize"
-then click, Connect to a Projector or Another external Device
-find that option and click, connect display