Graphical Corruption w/ drivers installed?

[PrinnyFlute]

Alright, so after installing a new PSU my system failed to boot properly; it would stop at the Windows loading screen, but could boot into Safe Mode fine enough. It was also (and still is) getting some really funky graphical corruption when the system was powered on or off, making the monitor look like it's burning or something.

After hours of labor I pinned it down to my newer Palit GTX260; with it removed the onboard video loaded just fine into Windows. So more testing from there: I uninstalled the drivers, which let it successfully boot from the card to Windows into 1280x1024 resolution (Further testing shows that without the drivers scrolling windows are choppy but videos and 3D Flash games run smoothly?). Once I reinstalled the drivers things got a bit weirder:

I've tried multiple versions of drivers with no seeming difference. When drivers are installed for the card, the Windows loading screen becomes visually corrupted and the booting stops with the screen mostly blank with a few white lines. I can boot into VGA mode with the drivers installed: the screen is littered with small lines, but is still visible.

Now no matter what I try this is pretty much the situation. Drivers = corruption, no drivers= Works fine in limited specs. I know that bad VRAM can cause these sorts of problems, with the system picking up the slack when there aren't any drivers, but I was wondering if anything else could possibly be wrong before I RMA this thing? Or any solutions other than sending it in?

 

[mister g]

Tell me what PSU did you install over the old one. It's unusual how bad VRAM would start after you install a new PSU.

 

[PrinnyFlute]

Yeah, that's what I thought. I installed an Antec Earthwatts 650? The power supply is working fine, and I've tried it with both old and new PSU's and it's the same either way.

 

[mister g]

I'm sorry about that, can you boot into the motherboard setup menu? It may or may not help but did you set it to disable onboard and use the graphics chip's output signal?

 

[PrinnyFlute]

I can get into BIOS no problem, really. Assuming that's what you mean.

It's already setup to only enable onboard when there is no graphics card present, but I might try turning it all the way off to see what happens. Again, the only problem is with Windows, though there is some crazy visual effects immediately following when the computer is turned on or off; not long enough to impede anything else, though.