Anyone know which sounds match which chips...

modessitt

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...on a Bally/Midway Space Invaders? Mine keeps playing the UFO killed sound, and I need to replace it. I think I have a schematic for the L board somewhere, but figured I'd ask here just in case I don't...
 
Found this info, hope it helps...

Missile Shot Sound: Check the lm3900's at M4 and P4 If you get just a high pitch for the missile shot, check the 4006 at n5

Thump-Thump Background Sound: Check the lm556 at H4 This is a dual timer of the 555 series and uses a bus control to set the rate of the sound.

Base Explosion Sound: Check lm3900's at K3-4 and K5

Invader Hit Sound: Check lm3900's at K4

Saucer Hit Sound: Check lm3900's at M5

Saucer Sound: Check the 76477 at H2

Another chip to check if you just lose the saucer hit sound is the 74174 at E5 and the 7417 at F5, these can sometimes only partially fail with just one line going bad. I would suggest replacing these when you fix your board.
 
Thanks. I'll give it a shot.

Trying to get a few things in the gameroom fixed before people come over for Thanksgiving...
 
Thanks. I'll give it a shot.

Trying to get a few things in the gameroom fixed before people come over for Thanksgiving...

I've had pretty good luck piggy backing lm3900's to test sounds on SI. Save ya some de-soldering work and time.
 
I've had pretty good luck piggy backing lm3900's to test sounds on SI. Save ya some de-soldering work and time.

Well, I socketed it. No go.

I double-checked in MAME to make sure it is the SAUCER HIT sound that I'm hearing - only during game play.

I found my schematics, and it's going through the LM3900N at K4. Replacing it did NOT help. I traced back to the 7417 and 74174 but neither of them show a short. I may swap them out (with sockets) just to be sure. The big 76477 at H2 that generates the SAUCER sound may be next, even though I don't see how it would have anything to do with the SAUCER HIT sound.

I'm trying to find what generates this sound. The signal D3 seems to come in to the daughterboard on pin 27 of the interboard connector, then hits the 74174's at E4 (pin 11) and E5 (pin 11). Looking up a datasheet for the 74174 shows it outputs on pin 10 of each, and that the P33 signal on pin 10 of E4 goes through a 7417 at F4 then into the LM3900N at K4 before going to the amp. Pin 10 of E5 shows the signal P53 going into a 7417 at F5, going thru a resistor and diode before hitting a 566 at H4 and a 7411 at H3, then a few more resistors before going to the amp.

I tried tracing back to where the D3 is generated on the main board, and it comes from the 8216 at D3 pin 14. It comes from an input on pin 12 from pin 9 of the LS153 at C3. That output is fed from a combination of 4 data inputs and 2 address inputs. Of course, I have no idea which combination makes it play the SAUCER HIT sound. I've traced back each DATA input looking for a short - thru various chips - all the way to ROM 0 (one line) and I'm not finding anything obvious...
 
Well, I replaced the 74174 and that didn't help. Took the boardset to the game along with my logic probe, and it seemed that I was getting regular pulsing off of pin 10 of E4. Just for kicks I pulled the LM3900 at K4 to make the sound go away - and it didn't! WTF? So, I used that LM3900 top piggyback some of the other LM3900's, and when I got to the one at M4, the sound decreased quite a bit - but was still barely audible. As M4 was socketed, I pulled it and the sound went away, even with the K4 installed. I replaced the LM3900 at M4 and the sound is now working 100% properly.

Strange, as my schematics show M4 to be for the MISSILE SOUND, and that sound was clearly working normally when I played the game. Just have to replace the backlight (which I pulled for another game) and it's done.

Oh well, time to move on to a few other games that are acting up:

Robotron - I need to install the 4164 (they better all work as I barely have enough)
Lethal Enforcers - graphics glitches in game play
Q*Bert - plays the wrong sounds in certain spots
Tempest - turn down brightness
Gyruss - install interior cardboard bezel

Hopefully I can get everything working in time for Thanksgiving. if not, I can pull some from the garage to replace them with if they don't want to be reasonable...
 
Well, I replaced the 74174 and that didn't help. Took the boardset to the game along with my logic probe, and it seemed that I was getting regular pulsing off of pin 10 of E4. Just for kicks I pulled the LM3900 at K4 to make the sound go away - and it didn't! WTF? So, I used that LM3900 top piggyback some of the other LM3900's, and when I got to the one at M4, the sound decreased quite a bit - but was still barely audible. As M4 was socketed, I pulled it and the sound went away, even with the K4 installed. I replaced the LM3900 at M4 and the sound is now working 100% properly.

Strange, as my schematics show M4 to be for the MISSILE SOUND, and that sound was clearly working normally when I played the game. Just have to replace the backlight (which I pulled for another game) and it's done.

Oh well, time to move on to a few other games that are acting up:

Robotron - I need to install the 4164 (they better all work as I barely have enough)
Lethal Enforcers - graphics glitches in game play
Q*Bert - plays the wrong sounds in certain spots
Tempest - turn down brightness
Gyruss - install interior cardboard bezel

Hopefully I can get everything working in time for Thanksgiving. if not, I can pull some from the garage to replace them with if they don't want to be reasonable...

Thanx for the repair update mod! How do you sleep at nite with all this info flying around in your thoughts! lol
 
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