Halp! My Precision M6600 is dead!

I had an issue somewhat similar to yours, power on, a few blinking lights and system powers off no matter what i tried so dell sent me a replacement motherboard and that still didnt fix it. Turned out it was simply my power button that went bad, lol (underneath the board for my power button, it was slightly yellow). After i replaced that, all was well and now i just set my bios to boot when the power cable is inserted, lesson learnt.

 

Exact same thing has happened to my precision m6400. after I took out the video card and reapplied thermal paste. No screen, no bios but the power light is on. No blinking diagnostic lights to tell me what to look for either. I also took out the memory and switched them around. nothing. Its not booting into the OS because the hard drive doesnt blink either. No battery, just AC and that shows power. I had a replacement motherboard that was unopened and the same thing happens. No screen no boot, small initial fan burst.

 

I have since put in my old Quadro 3700m that I originally switched out and it boots into Vista. Mind you this is also on an entirely new system board I bought for $99 on ebay. But it boots and loads into Vista x64. My problem appears to have been the firepro m7740 I had put in a week ago to replace the Quadro, and am now planning to get a refund.