HDMI Problem Well, I've tried asking everywhere... might as well try here. I got the xbox360, worked fine with HDMI on my Philips TV. One day I connent the console to a PC monitor via DVI Adapter. Shows only video, no sound - as expected. I connect the console back to my TV set... HDMI was no more. My cable is fine, my tv is fine, I ultimately bought an RGB cable, which is no HDMI but the next best thing, and that's that. Remember this: the hdmi cable is all new and works with other xboxs, so does my TV. Is there a way to rerstore the f*&^%$#! thing? - I never ever messed around with TV or Xbox settings. Just plugged it in and played on hdmi.

Both previous answers are correct. The first reply should reset your video.

DVI connection is for video only, the HDMI cable should have red and white cables which when using an adaptor can connect to your PCs sound card at the back.

Your 360 is still set up to work on the monitor in which case change the settings back to (720 or 1080 for LCD TVs) while you are connected to the PC monitor.

The picture will not look right on the PC monitor once its changed to 720 or 1080 but should now work fine when connected to you LCD TV.

Ok i think you need to reset the video settings here is a step by step procedure which you can follow

To reset the display settings of the Xbox 360 console to the default settings, follow these steps:

1. Remove any discs from the disc tray.
2. Turn off the console.
3. Turn on the console.
   
   Note If you are using an Xbox 360 Wireless Controller, turn on the console by using the Xbox Guide button on the controller. Wait for the guide light to indicate that the controller has linked to the console.
   
   Note Make sure that you use the player 1 controller when you do this. The player 1 controller is indicated by the upper-left quadrant light on the console.
4. As the console starts, press and hold the Y button as you pull the right trigger.
   
   Note This action causes the Xbox Dashboard to reset the display settings to the default settings. The console then automatically restarts.