Title pretty much explains it. I have the power cable plugged in and the PSU on and I turn it on. The motherboard powers on, the fans start and then the CPU fan stops. 2 seconds later the chassis fan also stops and then the whole PC just turns off. Pressing the power button doesn't do anything and taking cables out and plugging them back in doesn't work. I somehow got it to turn on about half an hour later but it just did the same thing. The case and PSU are brand new but I'm using a motherboard that is at least 8 years old from the Dell Vostro 230s with the original CPU, CPU cooler and ram. The hard drives have been verified to work by a friend and all the cables are plugged in securely. I don't want to try plugging in my GPU just in case it fries it.