First time poster: Thought I'd throw this to you guys and see what we can come up with. I'm a bit of a NOOB when it comes to this stuff, but I'd say I know enough to get by with. Anyway, the problem is similar to an earlier post by Warger ("HELP!!! - Building a Computer and having troubles!!!!), in that I've just attained a new motherboard, hooked everything up. The LED on the motherboard is green and lit, but when I hit the power switch on my case, nothing happens. Nothing powers up, nothing boots. Attempted multiple setups with same results: First attempted with full setup. Took out PCI Slotted peripherals (network card, TV Tuner, Firewire, Audio Card). Took motherboard out of case, attempted to run w/ Video Card and Memory. Took motherboard out of case and attempted to run barebones (with/without Video Card or Memory (one at a time)). Took motherboard out of case and attempted to run with nothing (no Video Card or Memory). All roads lead to the same place: Nothing powers up. Any suggestions would be MUCH appreciated. Background Note: Reason for getting new motherboard - My last motherboard, for some reason, the USBs and Ps/2 ports didn't recognize, and though sometimes everything would run if I had just a keyboard plugged in, but when attempting keyboard AND mouse (in Ps/2 ports that is), nothing would recognize. And again, USBs were dead. However, computer booted and OS executed properly, everything else functioned fine, just had no keyboard or mouse or USBs. Computer Specs (I'll just put the barebones stuff): Asus A7v8x-x Motherboard (NEW) AMD Athlon XP 1700 Future Power - Input 115v/230v-, 6A/4A, 50-60Hz. Output: 400w. Model No: ESP-400ATXP3P4 Thermaltake Vocano 5 Heatsink/Fan DDR Ram - 256 Mb (x2) Nvidia GeForce 4 Thanks guys, good luck.