POSTs but won't boot

[SuprchargdMazda]

Reflashing the BIOS on my uncle's computer killed the board. So I swapped over the parts to my spare ECS PT890T-A and hooked it all up.

The computer recognizes both optical drives and hard drives, memory, and cpu. All good so far. Pop in XP, wait....wait...wait. Crap. The PC gets past POST but than all I get is a black screen with a blinking dash up top in the left corner.

The hard drive had XP on it before, so I was expecting at least a partial boot that would result in a BSOD due to the different chipsets between the motherboards, but I got nothing. Clearing CMOS didn't help any. I rechecked all my connections and everything is plugged in. I swapped the two IDE cables to the others' slot, once again the computer recognizes all the drives but I get the same result. Both the opticals and hdd's have one set to master and the other as slave.

Help?

Specs:
ECS PT890T-A
Pentium D805
Corsair 1gb ValueSelect DDR2-533
Hiper 580W PSU
eVGA 7100GS
10gb and 160gb IDE HDD's
IDE DVD burner and CD burner

[TwoRails]

Pop a floppy in there and see if it boots. I'd also pull the extra optical and HDs out, as well as having nothing plugged in but the monitor, keyboard, and mouse.

[SuprchargdMazda]

Already tried a floppy. Will try pulling the extra drives now.

[SuprchargdMazda]

Pulled secondary drives and the sound card. Still the same thing.

[TwoRails]

It didn't boot with a bootable floppy?? You might have to go thru the steps here.

[SuprchargdMazda]

Thanks for the responses, after taking a break I went back and it worked. I didn't really do anything new so I don't know why it worked but at least it's running.