Monitor sync rate

Dear all

I tried to configure X-windows in my machine. My configuration was successful. I worked some time in x-window. After sometime my monitor display is mess. i rebooted the machine. After that no disply. During the installatioin time it’s automatically detects my monitor type and sync rates. Now i am unable to use my monitor. I tried with some other monitor. It’s working fine. what could be the problem. pls. give solution.

regards
sakthi