Eliminator Sound Problem

Hi all,

Last night I struggle with a bizzarre sound board problem:

Symptom: Upon start up, no "bang" (Eliminator usually starts up with an
explosion). About 5 seconds later there is a slight "pop". About 10
seconds later, the audio begins to crackle, and it eventually becomes the
thrust sound. With the thrust sound running in the background, the game
plays fine, and the rest of the sounds are present. However, when a ship
explodes, the audio cuts out completely. About a good 20 seconds later, the
audio begins to crackle, and becomes the thrust sound and again, all other
sounds work like usual. In test mode, same thing: thrust runs in the
background. As soon as the test for "Small Explosion" triggers, all audio
cuts out, and about 20 seconds later, the audio begins to crackle, and
returns to thrust being the background noise.

I replaced the 74LS374 which selects the thrust sounds, the 7406, the TL082
near the output stage (U2), and all the electrolytic capacitors on the board
(except the 33uf), 2N4403 at Q5 and Q6.

I don't understand it. It seems like there is two problems: thrust in the
background, and small explosion cuts out all audio.

Of course, on the schematics, the Explosion circuits are labeled 1, 2 and 3.
Anyone know which circuit "Small Explosion" maps to?

Anyone who has the schematics, can you figure out how it is possible that
triggering "Small Explosion" could cut out ALL the audio? Any why it
returns so slowly?

-- 
Mark Jenison
---------------------------------------------------------------------------
** To UNSUBSCRIBE from vectorlist, send a message with "UNSUBSCRIBE" in the
** message body to vectorlist-request@synthcom.com. Please direct other
** questions, comments, or problems to neil@synthcom.com.