No green light =(

[HIM666HIM]

I cleaned my PC out last night all the dust and crap from the fan's...i put everything back exactly how it was, turned the computer back on and the power light wont go to green, it just stays on orange! The fans still going round nicely and the disc drive's still working so i have no idea what to do =( HELP

[ChuckFickens]

Check the RAM and graphics card is fitted correctly