真见鬼了。电源没反应了。

All components are new. The power was working last night and once this morning. Now it's like dead, but the optical mouse is on, and when I plug in the power cord in the back of the case, the keyboard lights lit. I kind of doubt the power supply is dead, then it must be the MB problem?

I connect all the power cable correct.(that's so simple) Here's some info of the system:
MB: Chaintech Intel 865PE socket 478 support HT
CPU: P4 3.0E
RAM: 512 PC3200