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Stern SB-100 Sound Board Tester (Arduino based),

AlanT

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Aug 8, 2021
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Location
South West UK
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AlanMusicMan
I am not sure where to post this. This is old Stern, not new Stern and thus is a bit Bally and .... anyway........

As part of sorting out the electronics on my 1979 Stern Dracula I had to address a particularly problematic SB-100 sound card which was not only faulty, but was also making one hell of a horrible noise when connected!
After floundering around a bit I found Wayne Eggert's excellent "Techdose" site which helps understand this board. On the back of that I decided to develop a test rig for these boards using a low-cost Arduino Uno.
The attached PDF document gives chapter on verse on how to make your own version of that tester should you need it. It also documents what changed on the board in respect of how it is reset (which none ofthe online schematics I could find seem to show) and which only exist in Stern engineering update #11 (and even that has mistakes).

In the end, my board turned out to have three defective chips, one op-amp and two on the address decode side. It also had one defective transistor and I changed out all the electrolytic caps and now it works like a champ.

Always open to questions on the tester if anyone has any - as not many of these about this seems like a good place to leave this document lying around for when someone needs it!
 

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  • Making a Tester for Stern SB100 Sound Board.pdf
    874.3 KB · Views: 5
Last edited:
I am not sure where to post this. This is old Stern, not new Stern and thus is a bit Bally and .... anyway........

As part of sorting out the electronics on my 1979 Stern Dracula I had to address a particularly problematic SB-100 sound card which was not only faulty, but was also making one hell of a horrible noise when connected!
After floundering around a bit I found Wayne Eggert's excellent "Techdose" site which helps understand this board. On the back of that I decided to develop a test rig for these boards using a low-cost Arduino Uno.
The attached PDF document gives chapter on verse on how to make your own version of that tester should you need it. It also documents what changed on the board in respect of how it is reset (which none ofthe online schematics I could find seem to show) and which only exist in Sterm engineering update #11 (and even that has mistakes).

In the end, my board turned out to have three defective chips, one op-amp and two on the address decode side. It also had one defective transistor and I changed out all the electrolytic caps and now it works like a champ.

Always open to questions on the tester if anyone has any - as not many of these about this seems like a good place to leave this document lying around for when someone needs it!
I forgot to post the Arduino code for the tester. To load it in to the Arduino IDE you will need to rename it ".INO"
 

Attachments

  • SB100Tester.txt
    8.9 KB · Views: 3
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