Strikers 1999 no BGM

PCB problems and fixes
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eggsanwich
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Strikers 1999 no BGM

Post by eggsanwich »

Hi all,

I recently picked up a Stikers 1945 III pcb, but the game has no BGM.

Everything else works as it should (graphics, sound effects, etc), but no background music ever plays.

In the sound test in the test menu, again you can test sound effects but the music won’t play when you test it.

The sound effects sound perfectly normal, no garbled audio etc.

Here’s what I’ve checked so far:
- Clear all data using maintenance code 81610
- Checked voltages on board, they’re fine
- Visually inspected board, no visible broken traces/lifted pins
- Reseated socketed roms
- Pressed on surface mount chips while board is on to see if music would be restored

Is there anything I’m missing? Suggestions for where to look next?
Hrvat9
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Re: Strikers 1999 no BGM

Post by Hrvat9 »

Where in Canada are you?
Take some pictures of the board :)
candy: Sega New Astro City x2, Sega Versus City (sold)
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eggsanwich
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Re: Strikers 1999 no BGM

Post by eggsanwich »

Hrvat9 wrote: December 5th, 2018, 6:47 pm Where in Canada are you?
Take some pictures of the board :)
I'm in Western Canada (Vancouver Island area)

Additional notes: I've tested this in my Blast City, Neo Geo Jamma cab and supergun with same results.

Hi res board pics here:
https://imgur.com/a/28iahDf

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eggsanwich
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Re: Strikers 1999 no BGM

Post by eggsanwich »

Reflowed the SOUND smt chip, no luck.

Would the BGM data be stored on the socketed roms by chance?

I don't have a reader/writer to verify, but can send them off to somebody who does.
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leonardoliveira
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Re: Strikers 1999 no BGM

Post by leonardoliveira »

The sound ROM is the SMD chip marked "SOUND". The soundchip is a YMF278B (OPL4) which is also a FM synthesizer. Without the ROM it is still capable of producing sounds. You would get some sound out of it if the fault were on the sound rom.

I think your problem should be at the analog circuits of sound output, not on the digital side.
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eggsanwich
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Re: Strikers 1999 no BGM

Post by eggsanwich »

leonardoliveira wrote: December 8th, 2018, 1:10 pm The sound ROM is the SMD chip marked "SOUND". The soundchip is a YMF278B (OPL4) which is also a FM synthesizer. Without the ROM it is still capable of producing sounds. You would get some sound out of it if the fault were on the sound rom.

I think your problem should be at the analog circuits of sound output, not on the digital side.
Thanks for clarifying. I am getting sounds, just not the music.

Analog circuits, meaning the area around the sound amp and Yamaha chip? I'll check it out see if I find anything. Thanks for the advice.
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eggsanwich
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Re: Strikers 1999 no BGM

Post by eggsanwich »

Success!

Had some help from XeD who was able to get the sound working again.

From his notes:

"Replaced small Op Amp. After reviewing everything, I did some reading. Found the dac and determine the analog side was bad. Work my way down from there. Music was right channel and fx was left"

Thanks for the help, all :awe:
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