I have a Sony Vaio PCG-f590 laptop that has been a work horse for me. I recently upgraded the Ram (a month ago), the hard drive (3 days ago), and the OS (from win 98 to XP home, also 3 days ago).
The computer worked fine for two days. And when I say fine I mean nothing was out of the ordinary at all, worked like a champ and I was so happy! Then yesterday evening I went to turn it on and got nothing. No lights, fans, HDD starting up...nothing at all when I pushed the power button.
I tried re-seating the ram, making sure everything was connected that I could easily get to from removing the keyboard, and I am going to get a power meter to test the adapter.
What is so upsetting about this is nothing happened to the computer from the time when it worked to the time it didn't. It was working literally 4 hours before this happened and was not even moved in the interim.
Am I looking at a power issue, ground, short, or what? I found this page with a similar issue but I cannot figure out how they fixed it: http://ask.metafilter.com/67063/Sony-Vaio-wont-boot-At-all