NBA JAM TE Sound Board No sound

[triforce7770]

Have a NBA JAM TE sound board that's not getting any sound unless I max the pot and get a slight hum. Sound IRQ Passes and still no sound
Things I done so far
*getting proper voltage to the board and 5v to main board
* sound board recap including axials from arcadepartsandrepair
* RIbbon cable is matching red side pin 1 to pin 1 each side.
* Ran hand under amp and getting feedback
* Re burned U3, U12, U13 (U12 and U13 were masked and U13 tested bad when i verify with my gq4x4)
* Changed all op-amps ( lm324, both tlc048n's)
* Changed am31's and am32's
* Oki chip looks fine no corrosion seen and traces test fine.
* Have a 50k audio taper pot installed
*Changed Clock Crystal

 

[stj]

i thought that era of games had digital volume control in the settings??

 

[Asure]

This one uses a pot.
Show your wiring harness for the sound board plz..

 

[triforce7770]

here are my pics of the main board and sound board and the wiring as well.

 

[ShllShockArcade]

Have a NBA JAM TE sound board that's not getting any sound unless I max the pot and get a slight hum. Sound IRQ Passes and still no sound
Things I done so far
*getting proper voltage to the board and 5v to main board
* sound board recap including axials from arcadepartsandrepair
* RIbbon cable is matching red side pin 1 to pin 1 each side.
* Ran hand under amp and getting feedback
* Re burned U3, U12, U13 (U12 and U13 were masked and U13 tested bad when i verify with my gq4x4)
* Changed all op-amps ( lm324, both tlc048n's)
* Changed am31's and am32's
* Oki chip looks fine no corrosion seen and traces test fine.
* Have a 50k audio taper pot installed
*Changed Clock Crystal

Triforce, running into a similar issue. Did you end up finding the fault? I’ll troubleshoot on my end and let you know if I find anything that might help you as well as me. 2 heads are better than 1

 

[ShllShockArcade]

here are my pics of the main board and sound board and the wiring as well.

Tri, I have two possibilities for your sound board issue.

I just noticed inductor L1 appears to be twisted and in contact with that capacitor.

Second, what are the EPROMs you are using For U12, U13 and U3?

 

[triforce7770]

the eeproms im using are the te edition roms, also the inductor on l1 isnt touching upon further inspection. i did sent off the boardset to see if it can be repaired from a person who is very well experience in midway pcbs. After looking over and trying to fix the issue he believes it might be something to do with the oki chip. he checked everything and rule alot of stuff out. I even changed out the oki chip and looked under for possible corrosion or something. nope it was clean. it might become a parts board at this point.

 

[ShllShockArcade]

Well so the reason I ask about the 3 EPROMs is because after a week of troubleshooting my board and doing exactly what you went through - re-burning all new EPROMs, changing out my amp and replacing all of the electrolytics I was about to give up. The board came to me with a bad sound board so I knew it didn’t work from the start. What I didn’t think about was that the original owner installed the wrong type of EPROMs Just out of curiosity I started looking at photos on eBay of peoples boards for sale and realized that the original owner had a different U3 than what I saw in the photos. He had ripped onto M27C4001’s for all 3 EPROMs … U3 doesn’t take a 4001 according to the photos, it takes a M27C010 …. So I was thinking well … what could it hurt … and sure as hell. All of the torture and torment due to 1 of the 3 EPROMs that was outputting at the wrong frequency. Trust me, a 4001 can easily be written to and verified for U3, but it doesn’t mean that the other chips will recognize it. Make sure your U3 is a M27C010. Worth a shot

 

[triforce7770]

It's a 27c010... uhhhh lol

 

[ShllShockArcade]

It's a 27c010... uhhhh lol

Well crud ….