However, I had some trouble trying to fit the PSU (had to take out the CPU fan) and the video card (had to move the hard drive up one "bay" and some wires).
Once I tried to turn it on the first time, my computer power LED flashed once. After trying to turn it on again, the LED flashed 4 times in succession. After that, the LED doesn't flash. The fans, hard drive, and etc don't spin and I guess my computer just doesn't get power.