Pc not working

Hello,
im having a problem with my system, and i was wondering if anybody can help me out with this.
Everything was working then i turn off it very carefully but next day when i open the computer it doesn't display the window and no power in keyboard, my desk top screen went black and keyboard, stop working but mouse has a power . The fans, and the light is on and running but nothing else work. I've clean and reassemble all power cable, hard disk , monitor cable is working and motherboard also contain power.please help to get ride on this problem. i have install window7 and it is an intel motherboard.