Computer black screen problem, Help required A.S.A.P

[electricfirebolt]

Well... I switched my desktop on as usual, then left it starting up whilst I went to the toilet for a minute. I come back only to be greeted with a black screen and the CD Drive led light flashing constantly. At first I thought the monitor was at fault so tested connections and plugged monitor into laptop, it worked fine on laptop, so then I tried replugging into the graphics card, still nothing so I plugged the monitor cable into the onboard graphics, still nothing... The computer is starting up and running but its not doing anything... The fans are working etc...

Please help

Maybe the heat has something to do with it but im not entirley sure as has 3 fans emitting and sucking air...


Thanks.

 

[electricfirebolt]

Anybody, this computer is considered pretty vital to myself :/