Waterfall video when connecting to TV
So I have an old Sony KDF-55WF655 55" projection LCD HD TV. It is supposed to support HD resolutions. The problem comes in when trying to use it as a monitor from my old windows XP pc. I have an old pc that I've converted into a media center just for practical use. It's running:
Pentium 4 3.0 Ghz
2.5 Gb DDR RAM
ATI Radion HD 3850
The display seems fine at first. I get the ASUS splash screen, and windows continues to load. When it get's to the user login, the video starts to waterfall down the screen(the default resolution was 1280x720). The issue did not occur in safe mode, so my assumption of a resolution problem was enforced. VGA enabled mode also proved successful. I changed the colors to 32 bit, and still no problems. Only when adjusting the resolution above 720x480 does the problem occur, and it happens immediately. It is actually so bad that I can't navigate with a mouse, and have to use keyboard shortcuts and blind navigation to change it back, or just cold boot it into VGA mode again. I'm assuming that the problem is that the TV doesn't support the resolution. I have looked through, and played with all of the TV settings, adjusting ratio, zoom, etc, and everything seems like it should be working correctly at high resolution settings. I have also searched everywhere on google and have not found a solution.
I have the computer connected S-video out to an HD component adapter, to the TV. The HDMI port on the TV is damaged, so there's no converting from DVI to HDMI. Hypothetically, let's say that I'm unwilling to switch outputs :P.
Thanks for any input, I'm at a loss at this point. It simply might not be supported above this resolution, but I'd like another opinion. Doing anything other than watching movies is impossible at this resolution.
PS: I searched the forums and didn't find a related thread, hopefully i didn't just look it over.