NBA Jam TE sound board issue

mustang_5l

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Please help...

I got a NBA Jam PCB and sound board from a lot of untested boards... The Main PCB works fine. you can play and everything works as it should. When I hook up the sound board it seems to work too... I can adjust sound pot and vol goes up and down. Now for the problem... While playing and setting up you can hear the announcer blurt out random names and actions... all in the wrong instances, like when you are running down the court and he blurts out 3pointer! When choosing team, he'll yell out other things not related to the screen you are on etc.. etc... game music is good, just the announcer part sucks and annoying... is this something to do with the soundboard and is it fixable? or should I be looking to replace the soundboard since they are relatively cheap now?
 
could be a few different things, i'd do the usual and clean all the legs on all the chips and reseat the ribbon cable (or even better try a different one). I haven't had one with the problem you have yet but i've had a few that echo and do other interesting things.
 
I've heard of this before. I think I even witnessed it back in the day.. which is funny, our NBA Jam "disappeared" and came back as an NBA Jam TE some time later. :) but yeah, I've heard the random sounds. in fact, the game even does it in MAME frequently, just not as much as you're talking.

but alas, I would check your voltages. pull up a manual over at http://arcarc.xmission.com/PDF_Arca...erations_Manual_(16-40023-101-b)_Jan_1993.pdf and get the wiring diagrams for where to check..

make sure the sound board has above 5.05V at the +5, the +12 is above 12.xxV, and your -5 is in the mix.

probably do what Broods says first though, make sure every socketed chip on your sound board is clean and inserted in all the way.

check my power supply guide in my signature too, if your voltages come up out of whack at the sound board, chances are they're wrong at the JAMMA edge too. dirty JAMMA edge will cause that, in fact, I just clean ALL my JAMMA edges with a pencil eraser just cause, you'll get more efficient power going to the board, and in most instances you won't have to drive the +5 as high on your power supply cause you won't need to compensate for it anymore.
 
Sounds like a timing issue. I had a problem like this before on a Neo Geo and it turned out to be a missing signal to the YM2610.

It's possible that the ribbon cable isn't making a 100% connection to the board. Check continuity pin for pin on the cable receptacles.
 
Ok. so here's the latest... I pulled the 3 roms off the sound board and put them into my known working MK1 sound board.... results: same issue with the annoying announcer.
So I'm beginning to believe that I don't have a sound board issue and the problem is probably with the rom chips. Thoughts?
Anyone got some good TE sound rom chips?
 
definitely interesting, i wasn't sure if you had another soundboard to test the chips in. also make sure your swapping the lil decoder chip in the middle of the soundboard too. they're different P/N from midway so i'm not sure if it's required to swap those two or not (i normally do).
 
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