Star Wars Sound issue

Mr Do

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Game works great, for weeks. Then turn it on and no sound. Then turn it on weeks later and sound works.
When the sound does not work, I usually hear a clicking/thump sound as if it is skipping like a needle at the end of a record or like something is trying to reboot.

Yesterday I heard just static when turning volume pot up.
What can be rulled out?
David
 
Game works great, for weeks. Then turn it on and no sound. Then turn it on weeks later and sound works.
When the sound does not work, I usually hear a clicking/thump sound as if it is skipping like a needle at the end of a record or like something is trying to reboot.

Yesterday I heard just static when turning volume pot up.
What can be rulled out?
David

blast from the past! I am having a very similar issue with mine...Did you end up tracking down the issue with yours? Thanks
 
sound

Had a bad sound chip.
Have to research which one it was.
 
Sound Chip

Pretty sure it was the TMS5220NL Speech Synthesizer, 28 pin.

Try reseating it or even borrow it from a good board to be sure.
 
Well, replaced the synth chip today (FYI they are avail at twisty wrist) and the problem remains unchanged.

Other ideas? I thought somebody mentioned a filter board issue maybe?
 
First, I would run the self test and diagnostics. See the star wars troubleshooting guide for info on both. The self test involves grounding the sound board's self test test point, and the sound diagnostic involves configuring the dips in a certain combination and grounding the diagn test point on the main board (#26 is the sound diagnostic - you'll see 26 flash on screen during the test). See what you can learn from that.

Then I'd start probing the sound board processor with a logic probe to see if anything which should be toggling is stuck, or if anything which should be high or low is opposite.

In my case, I had a bad processor and I could tell because the HALT signal was being pulled low. If I popped out the processor, it was high like it should've been. It might be helpful as you probe to look at datasheets of the parts you're probing, or at the very least you should be using the schematics as a guide for what to probe (page 15a/15b). Hope that helps some.
 
First, I would run the self test and diagnostics. See the star wars troubleshooting guide for info on both. The self test involves grounding the sound board's self test test point, and the sound diagnostic involves configuring the dips in a certain combination and grounding the diagn test point on the main board (#26 is the sound diagnostic - you'll see 26 flash on screen during the test). See what you can learn from that.

Then I'd start probing the sound board processor with a logic probe to see if anything which should be toggling is stuck, or if anything which should be high or low is opposite.

In my case, I had a bad processor and I could tell because the HALT signal was being pulled low. If I popped out the processor, it was high like it should've been. It might be helpful as you probe to look at datasheets of the parts you're probing, or at the very least you should be using the schematics as a guide for what to probe (page 15a/15b). Hope that helps some.


Good advice. Thanks

I'll do the test tomorrow and see what it does. As for logic probes etc, that's beyond my depth of knowledge. Hopefully of the test doesn't show anything clear I can find someone to work on it. Thanks again
 
I had same problem music and no speech and the video I posted was totally it. The 74c00 was totally the problem. Replaced and fixed. When not working I got clicks. This is a CMOS chip. If you have a probe just follow what the guy does in the two videos.

Edit:
My mistake it's a 74c04 @2F on the sound board.
 
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