New build: -Dataexcel mobo -PIII 450MHz cpu -64 Mb RAM -two HDs(don't know the size yet - the retailer said they're old.. ) -ATX case + 250Watt ATX psu -CD Drive and floppy drive Connected the 20 pin ATX power from PSU to mobo. Next, connected the power button and the beeper from the case to the empty mobo (no cpu, ram, cards or anything else). Turned on computer and: no mobo fan, no PSU fan, no activity of any kind. Added cpu and ram - same thing. As for diagnostics, we tried a known good power supply with its power button and 20pins plugged in. Failed to start - same results. The mobo is clean and looks brand new. Inspected it carefully for any cuts and scratches, and there wasn't even one. Took care to transport and handle it properly.
Well, I don't mean to sound offensive, but how did you expect the computer to start up without a CPU, or even RAM? By the way, make sure your video card is seated properly. I'm not all too sure whether a video card is needed to boot or not.
A computer can boot without cpu, ram, nor video card. The cpu fans will go on and the mobo will start to beep.
Have you tried to boot the motherboard on a non-conductive surface (like a closed motherboard box) and with just the CPU, 1 stick of RAM, video card, and the CPU cooler? I'm assuming you know the other parts are known good as well. Personally, I'm leaning in the direction that you just got unlucky and have a bad motherboard.
