My PC won't power up when I plug in my XLR8 graphic card. My power supply is a Corsair TX 750. I was playing a game, left the room, returned a few minutes later and my PC was off. Pushed the power button and nothing happened. I opened the case and discovered one of my fans with a flexible arm had fallen down on my XLR8. I thought my CPU and/or my motherboard died. I didn't find any errors when I tested my motherboard. I removed the XLR8 and turned on my PC and it worked. I turned it off and re-inserted the XLR8, plugged in the six pin connector to the power supply but did not connect it to the monitor. The CPU fan started but immediately died, then nothing. I turned off PC and unplugged the XLR8, hit the power button and alarm went off. I turned it off, removed it the XLR8, turned it back on and it works.
I would believe that the GPU would be at fault - it might have overheated due to the fan coming apart. If you have another GPU to test, that would confirm it.
I don't have a spare so I will have to buy one. The XLR8 has its own fan. I had to install it upside down. The fan was found resting on the GPU and leaning against the CPU fan. Could the fan cause a short and kill the GPU? Is it possible that it did something to my power supply? If a GPU is dead and plugged in, would it shut down the CPU and disable power until removed or replaced? I ordered a LED Power Supply Tester to check my power supply in case the fan was damaged.
Fans should be secured to the card - using thermal compound to ensure proper heat transfer. Just leaning a fan on the GPU will result in over heating.
My GPU has its own fan built in the card. The fan that fell is attached to a flexible arm that was secured to a motherboard's mounting screw. You can bend it to fit in your PC case. The extra power supply cables are tied together and stuffed in an empty bay. The case was moved during my absence. The cables must have worked its way out of the bay, landed on the flexible arm and the cable weight pushed the fan down on my GPU. My power supply was tested and passed. Lesson learned. Don't use a fan that has a flexible arm. Buy a ATX Micro-Case with plenty of space to install more than one system fan.