Status: Successfully repaired on 2/25/2021
I purchased an inexpensive Sega System 16 board with the game Ryu Kyu to use as a donor for the Apocalypse System 16 Multi game solution.
![](https://shootthecore.tech/wp-content/uploads/2023/01/IMG_0401-1024x623.jpg)
Unfortunately something was wrong with the sound effects hardware – they played with a crackling screeching sound. I connected an audio probe and started checking around the sound hardware.
![](https://shootthecore.tech/wp-content/uploads/2023/01/IMG_7809-1024x768.jpg)
I soon confirmed that the sound effects sounded fine coming out of the Yamaha YM3012 DAC, but sounded garbled after feeding through the TL084 OpAmp.
![](https://shootthecore.tech/wp-content/uploads/2023/01/IMG_7808-1024x768.jpg)
Schematics for the System 16 are available and you can see how the chips tie together in the schematic.
![](https://shootthecore.tech/wp-content/uploads/2023/01/Screenshot-2023-01-07-010307.png)
Replacing the TL084 OpAmp with a fresh part resolved the problem – now the SFX sounded crisp and clean. Another successful repair!
![](https://shootthecore.tech/wp-content/uploads/2023/01/IMG_7807-1024x768.jpg)