So my BIOS is broked, should I

Hey guys,
I’m trying to fix my cousin’s computer for him, and what I came up with is that his BIOS is missing some important compenents. So I tried to locate what BIOS is on his mobo, and I found “PhoenixBios D686 048223202”.
Now I’ve tried looking for BIOS updates and whatnot, but I seriously can’t find anything…

Please help guys, I’m not in the mood to go out and buy another mobo.