Jackpot Stampede Deluxe- No sound- I/O board issue

[Oldslot]

This is for a Williams Jackpot Stampede Deluxe. I have no bong or any other sounds working. After checking speaker wiring and speaker.. are ok.
My friend has a Jackpot Stampede. So I tried the i/o board in his... no bong or sounds.
I have checked what the manual says.. and looks ok.
What I need is a schematic of the i/o board.
Also any input on what this issue could be?
We checkered these things against his board... but not sure about thise tiny caps can be checked on board.
The game fully works except no sound... which stinks!
Even a replacement board or board repair service?
Nothing looks burnt or damaged. I included a picture. Thanks

[Oldslot]

Any ideas here?
Link to i/o schematic?
I/o board replacement or repair available?
Thanks

[playklax01]

I know it's awful not having sound, especially on this game.  I've owned WMS machines for decades and never had an issue (knock on wood) where it's actually a component on the board itself.  WMS may have it's weaknesses, but the boards have tended to be proven strong.  The troubleshooting manual is pretty useless when it's for home use games, they're meant for machines that are on 24/7 for months at a time in a rough casino (smoke/physically battered) environments.  And unless you're an expert at soldering these wicked small components, I wouldn't risk further damage.

You seem to have narrowed it down to the I/O board, that is good news, the problem followed the board which is what you want.  I know these may sound silly yet they're easily overlooked, but to get more 'easy' stuff out of the way 4 things to check are 1) look for any foreign matter on the top and bottom of the board.  Tape (big one!), any little piece of matter that could cause an unintentional bridge connection, and just anything that just shouldn't be there.  2) examine the bigger caps for any bulging (unusual, but not impossible).  I haven't run into this issue, but it could cause problems if you have them.  3) check the pins on the board going to the blind connector for any that are bent or missing, that would definitely be a problem.  4) examine closely the traces on the board for any broken ones.  Someone else had this issue on another machine earlier, and it really good some narrowing down to find it.  They bridged it with wire and problem solved. 

If none of these applied to your situation, your best bet would be to try to find a replacement board.  They are hard to come by, and tend to be pricey when they do.  But they do appear time to time.  Currently there's a bunch of Video I/O boards on there, be careful you don't buy those.  Keep checking and stock up on whatever you can get your hands on.  They haven't made these parts in over 25 years.

[dragster73]

Williams used the AD1851 chip in their slots and their pinball machines. This chip can be a common cause of sound problems, but before you start chasing and doing shotgun repairs it would probably be easier to find a replacement I/O board.

As I asked in previous responses, do you hear any pop ort hiss coming from the speaker, this would at least tell you the Amplifier is doing something.

Another problem with trying to repair your board is not having a way to do testing on it as it is in a cage and that makes it impossible to access any components for testing.

[dragster73]

I went and looked in my tote of WMS board and I see I have several I/O boards for your machine however I no longer have a Dot mation  machine. The good news is I have a friend near by that has my old Jackpot Stampede Deluxe machine. If you're interested I can make arrangements with him to test it.

Let me know.

[Oldslot]

Thanks for the last 2 responses.  There is no sound at all coming from speaker at any time. I will check the board for a broken trace or other things suggested. 
I was trying to locate a schematic of this board. Might make it easier to find the sound path.

[Oldslot]

That would be awesome if you had a board! Let me know the status. Thanks