If it "twitches" but does not start, this means your power supply detected an overload (or underload) and shut back down. This can be a bad power supply or a defective device attached to it or the motherboard. You troubleshoot by detaching things, pulling boards, etc., to see if the PS and CPU fans will run. The PS does need a load of some type so you cannot run it by itself. You can easily troubleshoot down to it's being the PS or motherboard but not beyond that without special tools.
Hello. I have a interesting problem with my computer. I know that my motherboard is powered because it has a light that shows if it's powered or not. When I push the power button my computer does not turn on. Here's the kicker (and I know this is important) my CPU turns a quarter turn and I can here my speakers being powered on but the computer does not turn on. Could anybody help?? Thank you.