Basically my computer is totally fine, except the screen is extremely dim, and it occasionally fades completely to black - but I can still do things (blindly), and the monitor light stays green throughout these blackouts. When it fades everything gets bigger and then it gradually fades away.
My motherboard chipset crivers are fine, and so is the compatability. I've reinstalled anything, and have even tried downloading some various things from nVidia, thinking there was a problem with the GPUs, but that failed to work as well.
Any suggestions?

Please tell us if the "screen" is a laptop screen or a traditional tube-type monitor. If it's the later, connect it to another computer and see if it exhibits the same sysmptoms. If so, the internal circuitry of the monitor is probably failing.

(traditional monitor.) I've connected it to 2 other computers and the problem goes. A failing monitor seems to be the only advice I can get, but I know that's not it.

The exact symptom you described is usually a result of failing beam-drive electronics in the monitor, but if it doesn't happen when connected to other computers, then that diagnosis does become less likely.
Have you been able to connect another monitor to the computer in question? That would be the next obvious test.

your dim screen is caused by your inverter or your tube. there are websites that you can buy inverters or can repair the dim laptop screen.