My computer is not booting up...it doesn't show anything on the

my computer is not booting up...it doesn't show anything on the monitor screen...and my keyboard is also not working when I press the caps lock key or num.lock key it doesn't glow led light....as I read in ur post I disconnected all the cables from CPU and press the power key for one minute and then connect all the cables again and then try to start it but it not starts problem persist same as before.....every fan is working properly.....as in other post when I remove my ram(memory card ) from the motherboard and keeps it outside and then start my PC but it doesn't produce any beep sound....after that I place ram again into ram slot then problem persist.....and my computer was working properly before 6-7 hours when I used it after that I didn't start my PC but when I starts it it's not starting the problem happens as I told you above....I got harrased from this problem so please give me some solution to get rid from this problem....