|"When i removed Ram board beeped thrice"|
That's good. It means the board & CPU are probably still good. Make sure the RAM is fully seated in it's slot. Only use one stick for troubleshooting.
"But when i removed hard disk ,doesn't showed any difference"
You don't need a HDD to boot the board & access the BIOS. Leave it disconnected along with the CD drive & floppy (if you have one). Also, remove all cards & unplug all external devices except the keyboard. If possible, use a PS/2 keyboard rather than USB. Connect the monitor to the onboard video port.