I am having the same problem as brian was. I have an ASUS P4T533-C mobo with P4 3.06/533 chip 256 mb rimm and using a geforce ti 500? and a matrox millenium as another test card. neither card works to show output. I have only a floppy and hd hooked up, and have all the power plugs/etc plugged in correctly. what's weird is i swapped in a 2.4 Ghz P4 and everything worked fine, booted with no problems, that was about 2 months ago, but now nothing works at all. If anyone who posted might know what the solution to brian's problem was or could help me out, it would be greatly appreciated. I will try to answer any other information that you may need.
Btw i'm A+ certified, so i know what i'm doin. I didn't get any beep codes or anything, because it's not even getting to the bios to load post. I know that bad rimm might cause this, but nothing's been even touched in the whole comp for the 2 months beetween the time i tried the other chip till now.