This an old post but I saw it since I was looking for a solution to the same problem I am having with my Dell D520 core2duo laptop. The odd thing was that when I removed the memory from underneath the keyboard, it would startup. I tried different memory. The only thing was that i got it to work with just putting a 2 gig stick underneath and called it a day. I have no idea why the memory slot under the keyboard went. I have never run across this. I guess a first time for everything. At least it works, is all I can say but can never be upgraded to more memory. Diagnosed as a motherboard issue.