I purchased a new PS today. I took the MB out of the case so that the only thing hooked up is the power to the MB, the power switch from the case to the MB, and the power cord between the PS and the outlet. I press the power switch, the MB gets power for a split second, the diagnostic LEDs blink, and then it dies, same as it was doing before. I am assuming that this set-up is OK and that the MB should at least get power in this arrangement. Is that correct? If so, it looks like it wasn't the PS. Or if it was, I screwed up something else while trying to diagnose the problem. Guess I'll get a new MB now, a poorer but wiser man...
electronicchild, raiden, and, yes, Ste(!), thanks for your helpful posts. I hope they continue as I try to work through this problem. SHAWN, please refer to my earlier reply, as it applies to you as well. (I know, I'm not supposed to respond, but those "holy-than-thou" posts from the "experts" just burn me. People come here for advice and assistance, not ridicule. If you think someone is stupid, think it to yourself. If everyone knew everything, would we really even need a "Hardware Troubleshooting" forum??)