Need a little help

I have a abit nf7s 2 with an amd xp 2400+ I just put it in a new case, i changed the configuration a bit and when I went to start it up it get stuck after testing memory. it stops at memory frequncy ddr400...delete to enter startup does not work and alt-f2 to enter flash does not work...I reset the cmos several times. i even tried hooking up the old power source...same problem....what did I do?

 

How did you change configuration?
Reseat memory.
Double check all connections.
Any beeps?

"Changed configuration"? did you make any changes in bios, like mem timings?

 

I connected a usb2.0/ie1334(firewire) line, a new fan, i moved the pci placement of my graphics (verto geforce 4 mx400 64mb) and the soundcard (Creative Soundblaster Live !) and yes I do get a beep right before it freezes....I am using a wirless mouse and keyboard....could that be a problem?