S 2000 502 MPU

[Buzz]

Got a question about a S 2000 3 reel a bought 3 or 4 months ago, I've never had it working.  Did a clear and key, noticed I never heard the alarm.  Machine booted up and played fine but no reel sounds. Did all the usuall test, amp. speakers and speaker wire loom all OK.  Replaced that 502 MPU with a spare MPU now the audio works fine. Later in the day same thing happen again, but this time I had accidentally put the bad board in another machine. Today it happen again, after calling myself a bunch of not nice names for not marking the board bad, I realized I had marked it NFG. I have two boards doing the same thing, no audio. Does anyone know which component on the MPU controls the audio ??

Yesterday a completely different machine, jackpot switch would not turn off the alarm after a clear/key. This one also turned out to be a bad 502 MPU. ( I have a bunch of spares ) Found a burned trace on the back side of the board.

[Yoeddy1]

Buzz, were 363's installed?  Seems like I recall posts where "sound" issues occurred with other versions depending on the game, but 363 resolved the issues.

Jason

[Buzz]

Jason  I'm not sure what I was using, but I just switched all 4 chips from one board to the other and it worked.   I can retest with 363 tomorrow and post back the results. I hate to shit can the board if it's a easy fix.

[brianfink]

some times adding a sound card can bring back your sound to

[stayouttadabunker]

Jason  I'm not sure what I was using, but I just switched all 4 chips from one board to the other and it worked.   I can retest with 363 tomorrow and post back the results. I hate to shit can the board if it's a easy fix.

It's strange that just changing the chips brought the sound back on this one.
Could be just a bad chip?
It would interesting to see if the 363's "fix" it.
I have the same sound problem with one of my 502 MPU's.

[Buzz]

Bunker I think you misunderstood, I change the MPU to get the sounds using the chips from the bad board.

After reading this thread today I tried a new experiment. I installed a set of SG000363 and a VS011GX1 on the BAD board. Did a clear and key setup. Again NO sound. I had read brianfink  reply and figured that was a Dumb ASS idea, OK I've tried dumb idea's before.  It worked, after no sounds I installed a MM II sound board with a simm and the audio works as it should.  Not to let this thing get the best of me, I then removed the sound board. LOST all sounds with it removed. Re installed the MM II without a simm, now get the old standard reel sounds.

Brian  I guess your dumb ass idea wasn't so dumb  Thanks 

[stayouttadabunker]

Hmm...so all I have to do is put in an MML2 board then...
How it works for generic sounds without a SIMM card is beyond me. 

[Foster]

Sounds like a bad trace or component that gets bypassed with the MNLB2 in place
Has the board been reworked for the audio fix on the solder side.
there will be a couple wires going to the big AMP connectors that plug into the motherboard. if so then one of them could have come loose or been damaged.
there is like 4-6 jumpers installed and a resistor if I remember right. I cant find the document that explains the rework from IGT.

[stayouttadabunker]

You know...I've always wondered about those little green wires myself.
I posted about them 2 years ago with pictures too!...but never got an answer.
I will never be able to find it among all the bloody posts I've made over the years...

[brianfink]

another thing I have noticed it seems this fix does not work on vision machines witch dont have the amp in the top like my titanic it only brings back the enhanced part of the sound.

[Buzz]

Foster  The lower side if this board only has one mod. As I recall every 502 board I've looked at has this mod.  Notice it does go to the MM II plug. 

On the eprom side it does have this other mod, ( besides all the green wire mods ) but i'vve seen this same one quite a few times also. 

[Buzz]

I have a really bad 502 board so removed the wires and resistor ( first pic. ) from it and soldered them onto the ? board and that fixed the problem. The wires seemed to be soldered on pretty good so my guess is it was a bad resistor.