So, I went to turn on my computer this morning from a suspended state and it sounds like it turns on fine, but I get nothing on either of my monitors.
Here is my setup:
-AMD Phenom II X4 955 Black Edition Deneb 3.2GHz Socket AM3 125W Quad-Core Processor HDZ955FBGMBOX
-G.SKILL Ripjaws Series 4GB (2 x 2GB) 240-Pin DDR3 SDRAM DDR3 1333 (PC3 10666) Desktop Memory Model F3-10666CL8D-4GBRM -- 2 of these, on is only a couple months old
-GIGABYTE GA-MA785GMT-UD2H AM3 AMD 785G HDMI Micro ATX AMD Motherboard
-Antec BP550 Plus 550W Continuous Power ATX12V V2.2 80 PLUS Certified Modular Active PFC Power Supply
-Hanns-G HW-191APB Black 19" 5ms Widescreen LCD Monitor
All of the above is just over 3 years old (except the second 4 gigs of RAM, as mentioned). Plus:
EVGA GTX 465 (1 year old)
25" HannsG (2 years old)
Here's the behavior:
When I try to turn the computer on normally (with both monitors connected to GTX 465), I can hear it obviously booting up, but I get no activity on the monitors, the light never turns from orange to green to indicate that it's coming out of sleep mode. When I unplug one or both monitors from the video card and plug it/them into the integrated video on the motherboard and boot up, I get the BIOS screen and the OS splash screen, but I never get to it asking me to log in. I ended up completely taking the GTX 465 out and trying this and I get the same behavior.
For the record, I dual boot Ubuntu 11.10 (primary OS) and Windows 7 Ultimate, both 64-bit. The behavior is almost identical in both. Both get to the splash screen, but not the login screen. Differences: the Ubuntu splash screen is just the maroon background, there is no "Ubuntu" with the dots underneath. The Windows 7 splash screen is as you would expect it to look. Also, after the Ubuntu splash screen when nothing shows, the monitor goes to sleep. After Windows fails to show anything past the splash screen it just sits there, black, displaying no image but not going to sleep.
What I suspect:
I think I've eliminated the possibility of the 465 going bad and it looks like it's not an OS issue, either. I can think of 2 possibilities.
1) Some sort of motherboard issue. It's 3 years old and it's common among all 4 scenarios that exhibit similar behavior. But that's pretty crappy reasoning.
2) Power supply. That power supply (according to the calculator on Newegg) is not powerful enough to run my setup once I added that video card. After a year of being overworked (and underpaid) it's tossing in the towel. I'm more inclined to believe this is the issue. The fact that the moderately powerful video card outputs zero video ever and the less powerful integrated graphics output BIOS, boot and splash screen, but then nothing once there's some real computation to be done seems to support the power hypothesis.
The PSU is fine for your setup (newegg over estimates).
The problem is most likely your nvidia card is faulty. The onboard is ATI/AMD and does not run on the nvidia drivers. Boot into safe mode and remove the nvidia drivers and then it should run on Win default VGA drivers until you install AMD drivers.