Creative Inspire T3030 Subwoofer No Sound

Thread Starter


Joined Jan 3, 2023
Hi, I have a Creative Inspire T3030 2.1 speaker system of which the subwoofer isn't working. The two satellite speakers and volume control are working, as well as the headphone jack. Very unfortunately there is no schematic for this particular product online. The only references are schematics for a generic 2.1 sound systems like this:
which doesn't exactly match the product. It should be a good starting point regardless.

When powered on, I don't observe any component that is hot / smoking. There are a couple of strange things I observe:
- The pin 7 OUTPUT voltage of the bass op-amp (one of the 4558s) is about 10.67V, which is close to the Vcc of 11V.
- The voltage across the two different INPUTS (pin 5 and 6) of the bass op-amp are different by about 0.6V. One is about 3.4V while the other is about 4V. The difference was larger before I swapped the 4558 to a 5532 but I don't remember the exact numbers. I understand the 5532 has a diode between the two inputs to limit the difference. Anyway as I understand the INPUT voltages should be about 1/2 Vcc each and the OUTPUT voltage shouldn't get pinned to Vcc, so something must be off.

Things I already tried:
- Replace the 4558 with a 5532 like mentioned. No effect.
- Desoldered and checked several resistors and capacitors around the 5532 input / output pins 5, 6, 7. All good.
- Replace the volume control chip (M51132L) for the bass part. No effect.

I tested the speaker unit individually and it is reacting to an external DC voltage, so it should be good.

Before I attempt to reverse-engineer the whole schematic, any help from anyone who has worked with this circuit (I'm sure there are quite a few here: would be appreciated. Thanks!