I have a Intel d 915 Gav mother board it bios has become damage and now when I press power button CPU fan e.t.c become on but do not give any display or beep  
 
can some one help me how to restore my bios to its original position.

Uh, oh... last time it did that to me was when I lost the Bios. I hope that didnt happen to you! Look in your manual and find the jumper that controls the re set of the bios! Do what it says, and also remove the bios battery for a min, then re start.  
 
Good Luck! I hope you have a removable Bios chip! I didnt. 40 days later Asus sent me a whole new board, lol!
 
--Lupi!

^ I was doing some BIOS mods and killed the EEPROM. Fortunately the BIOS was socketed. So Gigabyte sent me a new BIOS chip for like $15-20. Too bad most of the EEPROMs these days are soldered. Seriously, manufacturs should put in socketed BIOS at least on the higher end boards (ie X48-DQ6).