The original sound board is pretty beat up. The reason the chips are missing is because they were corroded so bad they came apart when I tried to pull them to re-seat them. All the chip sockets need to be replaced. A friend had the known good taxi board. So I decided to try the Taxi board.
I don't think they are interchangeable. It looks like I will have to try to rebuild the old board. I found the following explanation on RPG:
<quote>
Found one thread relating to the problem I was having but it did not
have a solution but I used the Subject so the two threads would come
up together in searches. Upon further troubleshooting I have come up
with my answer and I wanted to document it here for future reference.
The issue I had was a Space Station background sound was dropping out
at random times during a ball and wouldn't come back until the next
ball. Tried getting all new ROMs from JWjr which did not help but
thanks for the great service as always John!
Next, I started comparing the game to my other SYS11's Taxi and Mousin
Around. I ended up swapping the audio board from my Mousin into the
Station and after quite a few test games everything worked great, no
sounds lost. I started testing components on the two boards to see if
I could come up with a bad component for why the one board did not
work and in doing so I noticed that the boards were not identical.
They are the same part number D-11581 but one had a number of
resistors and chips the other board did not have. Namely R18-21 plus
U6 and U18. (might be other parts but those stood out to me)
This board with the extra components was what the Space Station needed
AND I noticed that the sound in general was a good deal louder as well
and I had not turned the volume up. I took the board that was in
Station and put it in Mousin and it worked great in Mousin but the
sound, again without changing the volume control, this time was
softer.
So it appears there are at least 2 versions of these boards. Also note
that adding a few components to the board seems to boost the audio
somewhat as well. We can also see that they are not swappable both
ways, only one way. Mousin only needed the board without the
additional components but using theboard with the added parts did not
cause problems and actually gave the audio a boost while Space Station
just did not work properly with the audio board missing those
components.
Hope this can help save someone headaches in the future.
Al
I might as well add the other leg work I did to this as well. I went
through as many manuals as I have in electronic form and documented
which games use which verison of the audio board. I will refer to the
board with the additional components as 'revsion D' as I believe that
is what the board said on the back when I had it out of the game.
Original D11581 games
Big Guns
Banzai Run
Taxi
Earthshaker
BK2K
Elvira
Mousin Around
Game Show (11C)
Pool Sharks (11C)
D-11581 revision D games
Space Station
Cyclone
Sword of Fury
Whirlwind
Rollergames (11C)
Riverboat Gambler (11C)
Any 11B and 11C games not listed are because I do not have manuals for
them.
On a side note I noticed that Jokerz! used audio board D-12338
according to the manual, strange. Part number seems like an earlier
version of the next generation of audio board that they used.
Al
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