I have a Sony Vaio laptop - not sure on exact model as I am not at home currently - can post later if required. I have it dual boot running Linux (Ubuntu 12.04 LTS (Precise Pangolin)) and also Windows 7. I upgraded the Linux version to the LTS about a month ago. Before that I never had any issues like what is happening now althouh I dont think the OS upgrade is related to my current problem but it suppose it could be.
Basically when I power on my computer - it shows a black screen, sounds as if it is trying to boot, then the fan kicks in briefly for approx 3-5 seconds but then it stops and the green power light around the power button over on the left of the keyboard goes off. I have tried with the Battery out and connected to just mains and get same result. I have tried with just battery and AC not plugged in and same result. I have double checked the CD Drive to make sure its is empty - there is no usb or anything else connected. Anyone have any ideas of things I could try to work out what is going wrong. If any more info is needed let me know and I will try and edit the question to provide this.