The company who made the board has a website. Most motherboard manufacturers post their beep codes on their website.
We have seen a number of computers destroyed when unplugged in that manner... particularly MacIntosh machines, but some Windows machines as well... It appears that a spark follows the plug out, and electrocutes the motherboard when the spark reaches the case or anything vital.
I would be very suprised if you can fix that computer without replacing the motherboard.