I just recently purchased a new GPU for my computer (VisionTek HD 6770) and it's mostly for gaming. I installed it, but sometimes when I boot up the computer the graphics card isn't recognized, meaning the monitor is on but it only displays a black screen, as if the standard VGA connector has been unplugged (which it has not been). This usually happens when I am playing games such as battlefield 3, as soon as I quit the game and it exits fullscreen, the monitor goes black and a VGA symbol in the corner of the monitor flashes as if the VGA connector has been unplugged. I have no idea why this keeps happening.
I wanted to rule out a faulty graphics card and monitor, so i used my integrated Intel HD graphics, went into BF3 and exited, and it went back to the desktop. No problems there, so it isn't the monitor. As for my graphics card, I hooked it up to my brothers desktop and it worked just fine when exiting fullscreen. This leaves me to wonder if it is my computer's power supply, which I'm really hoping it is. I currently have an unkown brand PSU that has a 300W peak. The graphics card retailer insists on a PSU of 400W or greater, however I went onto a PSU Watt online calculator that would show me how much power I need for my system and it said that i would only need 280W max, GPU and all. Are there any ideas/solutions to this problem?
Note: I have purchased a 480W Logisys PSU and it should be here by next week.