VECTOR: Space Duel Sound Issue

Hello Everyone!

I just got a chance to test my "working" but sold "as - is" Space Duel 
board (from EBAY).

It's got a problem (surprise!) I wanted to run past you guys to see where 
someone might get started in diagnosing this problem:

The Space Duel board has good video, coins up and plays just fine.

The explosion sound that is normally heard when destroying "space stations" 
or when being destroyed is an incorrect low frequency bloop noise.

The only other problem I see with this board is when the game is completed 
and you normally get the cool "fireworks" show with all the explosion 
noises, with this board, it does the fireworks show but it is only 
displayed on the left side of the screen in a 2" column.  The rest of the 
screen is blank.  Of course all the explosion sounds are still the weird 
bloop noise.


So,

1. Do you think the problems are related or are these 2 separate problems.

2. What are the chips responsible for the explosion sounds?


Any advice is greatly appreciated.

Regards,

Steve Winslow