One day when I decided to turn on my PC, something strange happened. All the fans were running, but I had a blank screen. I then heard my graphics card's (ATi 5770) fan go in to a loop, turning on for a second and turning off for a couple more. It would do that for a couple of minutes, until it decided to get much louder and my PC started to boot normally.
I thought nothing of it at first, but then it started happening much more regularly, and it would take longer to power on each time. Today, the same thing happened. When my PC finally booted, it BSOD'd after a couple minutes of usage.
I opened my PC and checked all the connections. I cleaned out all the dust but I'm still having the same problem. Is this more likely to be a PSU or graphics card issue?