Chosen Solution
My PC was working perfectly until I plugged a PS3 hard drive in it with a SATA 3 cable. Now it turns on but the monitor doesnt show anything. I turned it off and removed the PS3 hard drive and it still won’t display anything.
If you disconnected all the cables in the back make sure that your display is connected to the right output, maybe you have a PCI Express Graphics Card and you forgot the connect it there and is connected to the motherboard output. (Happens to me all the time). Good Luck
