Good day, my dad just got me a new PSU which I of course installed. After I thought I had everything plugged in right, I gave it a boot... and to my surprise all it did was making the startup noise (I suspect the fan), and it didn't show anything on my screen. We then both put the older PSU in, which did the same thing. The new PSU contains 520 Watt, while the older one only has 150. I also installed a new graphic card with it, but that doesn't really seem to be the problem, since I also tried booting it without the card. The new Graphic Card is an ASUS EN9500GT if it's any use. Help is much appreciated.