I just bought a 32" Dynex HDTV to be connected to my PC. The PC has a HD5670 in it and has been connected to my 42" Phillips HDTV, as well as another monitor via DVI. With the PC connected to the monitor, I connected the HDMI to the Dynex, and both displays went black. The HDD was still working, but I couldn't get the display back. I forced a reboot, and the Windows 7 and BIOS screens came up on both displays, but as soon as the desktop would load, both monitors went black again.
I rebooted again with just the monitor and it worked fine. Then I disconnected that and connected the Dynex and the tv goes black with no signal. I reconnected the monitor and nothing there.
After re-installing drivers, updating the BIOS, running through Driver Cleaner, etc. I do everything I did before with no success. To make sure it isn't the PC, I grab my laptop, and try the same thing with it and the same result happens with the laptop display and the Dynex having no signal.
Finally, I go back to the PC, connect the Dynex, start in safe mode and it works. Reboot normally though, and the display goes black and won't come back until I reboot. Also, my PS3 comes up on the tv, along with my cable box, so that can't be it. Please help!
I appear to be having the same problem as this user.
I have for about a year been using a Dynex TV as a second monitor.
I just switched from my old HD 4670 to a HD 6850. It worked perfectly until I updated my drivers and now when I try to do anything through the TV, both displays go black. My advice to the OP, if you see this(I know this post is a bit old) is to try rolling back to older drivers. Sadly the ones I'm using are 10 months old.(the ones that came on the disk) and the recent drivers won't work with my dual-monitor setup, which is sad because the newer drivers increase my FPS in most games by 10-15.
After experimenting with different drivers, I've found that the 11.1 drivers are the most recent ones that work. Anything past that and I have this problem. Updating to say that the most recent ATI drivers (11.6) have fixed this issue.