TECH: Sinistar Sound - Jacks and foil?

Tombo

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I am troubleshooting sound on my Sinistar. I have the logic probe on 10P3 to see what happens during the sound test. Each test reads "low". The troubleshooting chart suggest to check the Jacks and Foil.

What exactly are the Jacks and Foil?

Thanks!
Tom
 
If I had to take a guess.... Jacks could be the header pins and Foil would be the circuit traces.
Basically make sure everything has good continuity.

And do you mean 10J3 ? The cable from the ROM board to the sound board ?
If so, that would be the input (trigger) signal from the ROM board, I don't think it will show anything during the on-board sound test.
But you can ground each of those input pins and see if it produces a sound.(pins 2-8)
If it does not produce a sound then you have a problem on the sound board itself.
 
The jacks are the header pins and the foil is referring to the traces. The sound board was notorious for flexing when the connector from the ROM board was attached. This flexing would cause cracks in the traces near the header.

You can put the logic probe on the individual connector pins (when the cable is attached to the ROM board and watch the lines pulse when the sound test (in the game diagnostics) is running. If you press the reset button on the sound card a single sound will be produced, but the lines on the input connector (from the ROM card) will not fire.

The other place to check with a logic probe is the output pins from the PIA to the D/A converter. If you are not seeing the data lines pulsing when sounds are supposed to be playing, try replacing the PIA. If you are seeing the output lines pulsing, check the input line to the amp with a scope or a very fast voltmeter. If there is a signal ther, then try replacing the amp chip.

ken
 
That's great nomenclature.

Wouldn't hurt to reflow the "jacks" with your fire iron while you've got it on your credenza.
 
If you press the reset button on the sound card a single sound will be produced,

Oh, I forgot about that...
The sound test button doesn't produce the series of multiple different sounds like most Williams games, so don't expect much from it. (it'll bleep and then act like it's dead) You have to go in and use the sound test in the service menu.

And a bad speech board can cause missing sound as well.
So re-seat it's ROM's and cable and such too.
 
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