Sega Saturn Model 1 - VA2 (VA SG) - No Audio

I'm currently trying to fix a broken Model 1 Sega Saturn with motherboard VA2 (sometimes called VA SG). The issue it's experiencing is that no audio is coming out of the system at all. I've tried many things to fix it before coming here listed below:

1. Replace the power supply with a known working one
2. Verify that the Video/Audio cable is getting a proper connection to the appropriate places on the motherboard. This means the connector itself isn't bad. (Also tested the cable on other consoles)
3. Visual inspection of the motherboard for any visibly damaged components (found none)
4. Replaced *all* electrolytic capacitors on the left half of the motherboard where the audio CPU lives, as well as the audio mixer.
   
5. Replaced the BIOS. (Was a long shot really)

So as you can see, I've definitely given it my best shot to fix this thing, and I've near given up. The remaining ideas I have left to try are as follows:

1. Replace all remaining electrolytic capacitors on the off chance they are somehow connected to the audio line, even if they are far away from all audio chips I could identify.
2. Maybe it's the RAM chips? How would I know? Are any specific to audio, since everything else seems to work fine?
   
3. Maybe replace the ceramic or tantalum caps? These are much less likely to have failed, and are difficult to replace, so I'm hesitant.
4. Verify that the audio chips are getting appropriate voltages (difficult since the power supply is blocking them when installed.)

If anyone has any other ideas, or suggestions as to where to go from here, I'm open to it. I've also got pictures of the board from before I replaced the capacitors. They're in this Imgur album.

 

This sounds dumb, but is your ribbon cable backwards to the CD drive. I bought a broken Saturn a few days ago with no sound and static on boot; the ribbon cable was in backwards (folded incorrectly) and once I folded it into the correct orientation it had sound again.

 

Not at all dumb. I can say that it's not the ribbon cable though, as I've tested it with games, and they load fine. Also, I know that when the CD drive isn't connected at all, you do get weird sounds, but you do still get *something*. I've getting nothing at all. Thanks for the suggestion though!

 

Sound's like a bad sound ic