My brother tried to do a BIOS update. I dont know but something probably went wrong during the process and now, all my computer does is power on, no display, it wont even show the POST screen..

Firstly, BIOS updates are precarious at best (especially for older computers and is not a decision to be taken lightly. They are rarely worth the risk.
Here is are some links that "MAY" help you recover from "failed BIOS updates or flashes".
WARNING!!!
Flashing or attempting to recover your BIOS should be done by a professional. I do not urge or endorse the use of these techniques, have no affiliation with the writer(s), and cannot be held accountable for failure. Again...this should be done professionally!!
That being said, I wish you success either way. You may have to copy and paste or type the first one.

http://www.associatedcontent.com/article/2026282/how_to_recover_from_a_failed_bios_update_pg2.html?cat=15

http://www.biosman.com/biosrecovery.html

http://www.informit.com/articles/article.aspx?p=27188&seqNum=7

http://superuser.com/questions/29221/how-to-recover-from-failed-bios-update

http://www.youtube.com/watch?v=_tEr_souZy0

Good luck. Hope this helps you.