I have no idea how, but my PC won't switch on. Lights and fans flicker on for half a second or so, then go Straight off. I have tried making sure all of the plugs are connected properly, rebuilt the damn thing to no avail. The motherboard power light is on, so are the ones on the GPU. Only solution I have is that the power supply isn't supplying enough power, but I'm scratching my head here. Weird thing is, it worked fine last night when I was using it.