I bought a new motherboard and when i put in the 6600gt, there is no signal. While the 6600gt card is still in, if i switch the vga cable to onboard, it has signal and shows windows booting. I think there might be a problem with the psu (6 years old) as it is old and only has 300 watts or it could be a motherboard problem but im not sure. The 6600gt works on other motherboard that is old.
Although ive already did all of this, it still does not work. Today, I also got a new psu 500w so we can rule that out. Im probably just going to assume that it is a defective motherboard. Thanks guys for your help.