Re: XPS 720 fans blowing at max, hard drive wrecked
I think the previous poster meant the CPU heatsink. I assume you cleaned off the old thermal paste and applied new paste to the processors.
Do you see any front panel diagnostic lights? They should sequence as the system boots and should all be out at the end of the boot process. If any stay on then note that code and go HERE
<ADMIN NOTE: Broken link has been removed from this post by Dell>
for an explanation.
At the moment it does sound like a bad motherboard. Make sure that all the plug in componets are properly seated. You might want to try pulling out all the ram sticks, all the cards and unplug the power connections to the drives and power on the system to see what indications you get.
Pay attention to the color condition of the power button light
Note any diagnostic lights.
Do the fans still ramp up.