Computer powers but does not boot.

Hello,

I have a gateway desktop, intel pentium 4. A few days ago as i had just turned it on, it completely crashed and would not turn on. I left it for a few hours and tried to turn it back on. However it does not turn on. The monitor says no signal and when i turn the computer on the keyboard lights up but after there is no lights anymore. The fan works fine however it does not stop at all it continues to work as the first moment it is turned on.( usually it quiets down).. Help i want to be able to get my documents out.
Thank you

<config>Windows XP