2.1 subwoofer not sounding correct

pacificapilot

Prominent
Jan 28, 2018
2
0
510
I just got a used Cyber Acoustics CA3001 and the subwoofer is making almost like a lawnmower sound behind what should be bass. The way these speakers work is a single 3.5mm jack comes from the computer and is hard wired into the right speaker. A hard wired cord also connects the left and right speakers. The system runs on 9VAC 1000mA DC power. The subwoofer, which has speaker model YDDE78-9B, has an attached hard wired 3.5mm plug/cord that is plugged into the right speaker. It can be disconnected at the speaker.

I have cleaned the 2 3.5mm plugs, and ensured that all connections are secure. I have tried using wall power as well as a plug on a grounded power strip. Plugging the subwoofer directly into the computer results in extremely quiet playback, but is still audible, and correct.

Any ideas what I need to fix?

The back of the subwoofer speaker
ImR0An.jpg


The front of the circuit board inside the right speaker
GDJm7F.jpg


The back of the circuit board inside the right speaker
foB8bX.jpg
 
Solution
I would guess that the subwoofer amp is oscillating. Probably on of the chips on the circuit board. You can trace the subwoofer wires to the board and the circuit traces to the chip. If you don't know how to solder and aren't looking for a learning experience you won't be able to fix it.
I would guess that the subwoofer amp is oscillating. Probably on of the chips on the circuit board. You can trace the subwoofer wires to the board and the circuit traces to the chip. If you don't know how to solder and aren't looking for a learning experience you won't be able to fix it.
 
Solution

pacificapilot

Prominent
Jan 28, 2018
2
0
510


I can solder. What chip would I be looking for?