Fired up a new acquisition - a Stern IJ, only to find the audio completely missing, in addition to a number of lamps that will need replacing, per usual.

I can't figure out what's going on here. No errors are coming up in Diagnostics that indicate what the issue might be. The wiring seems fine on visual inspection, although I haven't traced it completely. Any suggestions as to what I might check to try and diagnose this?

Perhaps unrelated, perhaps not - but there are a couple of wires under the plunger that appear to be inappropriately disconnected.
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They are clearly different colors (GRN-BRN and GRY-VIO?) so I haven't attempted to connect them together. Some reference photos are attached.

Any ideas as to what's causing the audio issue? Or what I should do with these loose wires?

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Thanks for the tips! Yes, the volume buttons bring up the volume indicator on the DMD. Maximum setting still produces no audio, though. Let me take another look at the CPU/Audio board again and see if I see anything. I didn't when I went over it last night, but I could have missed something.

Alas, this is my only Stern pin. So I don't have any working boards to swap in for testing.

I checked connectivity on all of the speaker lines and they are sound, going all the way from the speakers to J10. Then I tested the voltage output on U50 and U51. It was reading 12.7V on P5 and -13V on P3. Those seem within range. Following wellarmed's tip, I then checked voltage on P6 of U16. It was a paltry 3V. It does appear that U16 is faulty, which is the 24Bit Audio DAC. If that went south, I can totally see how the game would go silent.

Sounds like my CPU/Sound board needs to go in for repair. I'm not nearly skilled enough to replace a component the size of U16 on my own.

Those disconnected wires are a red herring, and are probably causing minor mischief that I haven't played/troubleshot the game long enough to discover.

FWIW - This was the 24bit Audio DAC chip at U16. That was replaced and the audio on this game works fine now. But now I have a far more troubling issue with some damage to the playfield around the Ark...