Neo Geo CDZ sound issues

Hello, I recently picked up a Neo Geo CDZ with no sound for cheap. When I plugged in, I discovered that the sound was actually "jumping" as in sometimes there was sound and sometimes there wasn't. Also, when the sound jumped from one state to another, white noise could be heard. After inspecting the motherboard, I didn't notice anything wrong: the board looks clean, almost new, and the capacitors do not look damaged nor do they smell electrolyte like leaking ones tend to do. Still, I replaced some of the caps with new ones that I had lying around (I used caps with the same capacitance value but higher or equal voltage). Now I'm not getting any sound at all, but the console still works. I just tried to replace again the capacitors that I had replaced, but still no sound.

Is that a bad sign? Or do you think the problem could come from the sound circuit itself?

Thanks in advance for the answers!