I have a HP pavilion desktop. Motherboard is a M2N78-LA. Upgraded power supply to 550w, previously had ATI 55xx series video card. Installed a new GTS450 last night. Stock ram, stock HD. 3 days ago I started up the computer and found that EVERYTHING has a green tint to it. I re-calibrated and researched and found that there is no blue signal coming from the computer. I replaced the normal video cable and went with a HDMI cable. Still green. I went out and bought a new video card (the GTS) and installed. Still green. I tested the monitor on another computer and it works fine. What else could it be? The computer is less than 6 months old and has worked fine up to this point. Even after the upgrades it was running great. It was purely after the boot up that the green issue came up. Any ideas? The only other curious thing is that the sound from the monitor wont work. I can plug in headphones and it works, but no sound from the comp to the monitor's built in speakers. The audio settings in windows show there to be sound sent.