(Just posting this here so people in the future can find it.) I replaced my motherboard and just wanted to leave this here for future reference to some poor soul who has to do the same.
If you replace the motherboard on your Dell Studio XPS 8000, [Admin NOTE: Service tag removed per TOU policy] and you need a new motherboard you can use an INTEL DQ57TM, it's compatible and I did a successful transplant. Your processor is an INTEL Core-i5 750 CPU 2.67GHZ it uses a SOCKET LGA1156. It uses DDR3 memory.
Once you take out your old motherboard and disconnect all those usb and audio wires and the power button wires. To hook up your USB front jacks, audio jacks etc.... here's which blocks go where:
Wires from the audio jacks and usb ports go into these colored block connectors, and those connectors get plugged into those little rows of pins/jumpers called Internal Headers. Every motherboard manual tells you about them. Grab the manual for your new motherboard and it'll tell you where your audio1, usb1, usb2, usb3, usb4 Header connectors are they look like 2 rows and 5 collumns of short little pins. (They almost always have 1 or 2 pins missing on purpose.)
the wires leading to a YELLOW BLOCK gets plugged into the audio1 header on your new motherboard, it's for audio jacks on top of the computer
wires with the WHITE BLOCK gets plugged into the usb3 headers on your motherboard (they are for the usb jacks on the very top of the computer tower)
wires with the GREEN BLOCK gets plugged into usb2 headers/jumper connectors (these are the 2 usb ports on the front of the computer beneath the cd rom drive)
wires with the PURPLE BLOCK gets plugged into usb1 headers/jumper connectors, i think it was for the sd memory card slot.
And now the hard part: the Power Button, Power LED light, and Hard Drive LED light are all colored wires bundled together leading to a black block that plugs into the FP1 jumper header. But it's a different order so you'll have to readjust the wires on the black block before you plug it into the headers.
Get a tiny little flat head screwdriver and carefully lift up all the little clips to undo the colored wires from that block and free the wires. Now put the wires back like this:
HD LED Light = Yellow + Black wires
POWER ON LIGHT = White + Red wires
POWER BUTTON = Brown & Blue wires (with an additional blue wire that offshoots, it should be plugged into a little jumper usually called "Alternatte Front Panel Power LED" with 1 little piin for (-) and 1 little pin for (+). Put that extra blue wire offshoot on the (-) minus jumper.
(If you don't plug it into anything the power button led will shine yellow, making you think something's wrong. )
ok that's all. bye bye.