Hello,  I have taken in a Ms. Pac man cocktail version that is pretty much all original from 1980 something. I think it has had a new monitor sometime but not sure. this unit has been in my uncles bowling alley for about 20 years or so. It has gum, scratches and all kinds of damage. I would like to clean it up and have it in my home for fun. 
The sound doesn't work. The speaker is disconnected. When I hook it up, it is a solid tone. I tried a different speaker with the same results. 
The monitor is in ok shape.  It has a little burn in.  I heard that these can be replaced with LCD's...  What does that cost typically? 
The main thing I am wondering is to know if the sound is ecomomically viable to fix. I am sure it is fixable, but what would that cost to replace the sound card? 
Is there an online resource for parts?  Thanks for your help.
Ryan