Re: Sega Universal Sound Boards

I use an audio signal tracer for hunting down problems on sound boards. An
old Heathkit that I made thirtyish years ago still works fine for me ;-)

You can even use the sucker as an audio logic probe...in some cases you can
actually hear parts of the sound generated on the data bus.

Force the sound by making a simple switch for the control logic (if
applicable). Works nicely on Space Invaders (O.T., but an example ;-)
sounds which are generated with a series of LM3900's, some of which are
audio noise/tone generators.

John :-#)#

At 09:59 PM 13/05/2003 -0400, Mark Jenison wrote:

>Hi all,
>
>I've been struggling with debugging 16 Universal sound boards. A good
>number of them mostly work except for the explosions, which create a "bong"
>noise instead of the appropriate explosion in Star Trek. In Tac/Scan, this
>problem effects the thrust noise, which creates a "rrrrr" sound. Apparently
>the problem is related to a white noise generation on the board, but the
>chip that produces the white noise appears to be fine, so it must be getting
>screwed up somewhere else on the board. I'd appreciate any debug tips for
>this problem that anyone can offer.
>
>Does anyone else here have any experience working on these boards? I'd be
>interested in trading repair tips or logs.
>
>I'd also be interested in working a deal where I could get a few working
>ones back in exchange for the rest (or maybe for some other boards).
>
>Last but not least, can someone recommend a chip search engine? Google
>seems to not be very helpful when searching for chips. In specific, I'm
>looking for MP7524 (schematics say AD7524, so that'd probably work as well,
>or any cheap cross that would work).
>
>Thanks.
>
>--
>Mark Jenison
>
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Received on Tue May 13 20:49:46 2003