compal fl90 won't boot - black screen

hello,

Today as I was playing COD 4 the screen stopped so then I shut it down and tried to start the machine again like every usual time but it won't boot right now. I can just hear cd working, hdd working and then nothing : screen remains black and the laptop is not working - I mean it's not the GPU failure because then I would get logged on to the windows (log on sound).

Now in my fl90 I have ati 3650 replaced like month ago and ever since it was working without any problems (in games or not).



What do you think ? Is it the MoBo ? What could possibly broke down ?