Which part of my computer is broken?

[Junkhead29]

Recently while I was on my computer I realized that the resolution had been changed. When I tried to change it back to 1440 x 900 the screen would go black, then it would go back to the lower resolution and say something about my Nvdia drivers not responding. I turned the computer off but when I try to turn it back on, the monitor backlight lights up a little but the screen stays black, and the Dr. Debug on my motherboard (asrock Z77 extreme4) says error code "b2." The graphics card (Nvidia GTX 660 Ti) turns on and it's fans start spinning, which makes me think it's not dead, but if I plug the monitor into the integrated graphics, the computer boots up perfectly fine. No error code, no problems at all, which makes me suspicious of my graphics card. I am also supicious of my power supply, because for a few months now the fan in the PSU hasn't been spinning. It doesn't spin when I boot the computer, and when the computer is under full load, it acts like it's trying to spin but doesn't. I can see the fan blades trying to spin but it seems like they can't. So I'm wondering if anyone could use this information to help me figure out what it is that's causing my problem so I can fix it as soon as possible.

Edit: I already tried reinstalling my GPU drivers and it didn't help.

 

[NBSN]

Looking in your manual the Dr. Debug error code b2 means Legacy Option ROM Initialization. Searches online say that it would probably be the PCIE connection and that they could not fix it. Other people say that the part affected should be displayed too. I don't know who is right or wrong. But I would suggest trying to use the on board graphics to see if that works to rule that it is your gpu or PCIE gpu connection. Then try contacting the motherboard manufacturer and see what they can offer as the best fix for that error since it is more than likely related to a motherboard physical or bios issue.