Did u go thru game setup? I think sound is #18.

Turn game on. Open coin door. Push the small button inside. This will start set up. Look at backglass and push button until you get to 18. Then push the start button until the other number goes to 3. That will turn on all sound.

I will have to check mine. I will in about an hour. I had to get my board worked on and there is a great guy here on pinside who does it for $45. I will get u his info. You will probably need a new reverb board (the one on the right side) and there is a guy who sells them on ebay for $100. They cant be fixed cause they have obsolete parts.
It is a beautiful game and the sound is really cool.

Your U3 chip is in the U2 spot...move it over.

The rest of the board looks okay...however you need a cap kit with new pots. Replace the connectors and then try it..without the SIA board plugged in.

There is NO sound without connected (properly) cable to "Say it again" board.

It's god idea to eliminate "SIA" board instaling FF jumper on "S&T" sound board

edit :
Sorry, after I take a look at photo , FF jumper is already there

Here is mine. image.jpg

I would not bypass the reverb board. It makes it a one of a kind game.

At "IMG_2247.JPG " at the top (did not see it at first moment..sorry )

Did you checked speaker ?

ABSOLUTELY.... but now, there is NO sound ( temporary bypass

Good luck with your sound problem, Centaur is a great game and I'm sure you'll enjoy it once you have it working properly. I'm not much of a tech so can't add much to help you sorry. I just wanted to make sure you didn't forget the sound pot in the coin door also. It's right next to the red button inside the door. Clockwise will turn it up.

Barakandl is the pinsider who fixed my board. Great job, big help.

The reverb board (it says say it again on the board) gives the game sound an echo effect. It is the board mounted to the right of the sound board.

I know I'm coming late to the party, but did anyone check the pot in the cabinet? maybe they just had the thing turned all the way down?

with great care ( the legs break) ..reseat U8

if that doesnt help its probably time for a good tech to do new rom sockets but a bad U8 will quiet the board and they are hard to find.

also note the test button on the board will make it do a test sequence of noises.

Not sure if anyone has made this clear in the previous posts but Centaur does not require the AY38912 ic in U12. If installed in a Centaur S&T, the board will still function correctly exactly the same as if the ic was not present.

This chip was used in some of the other games that use the S&T board like eight ball deluxe ect.

And connections...( S&T J2 pins 1&2)

Is there ANY "noise" , hum...whatever, when you move volume pot ?

Well, I have good news if your interested in swaping out the card. I rebuild the S&T for rustylizard a while back and he burned new sound roms for centaur to test it in his machine. I'm pretty sure he still has it laying around if you wanted to talk to him and see what it would cost to trade it out. At least that way you know you have fully working card.