Subwoofer Amplifier Repair Help!?

Thread Starter

Rewiu

Joined Dec 1, 2023
1
Can you tell me if it can be repaired and if so, what parts do I need? And for the context, my subwoofer started making a loud noise when is on. I opened it to look at the amplifier and noticed that there was a melted brown substance that I removed, you can still see the traces where it was. And now I see that some parts at the base are melted!? What can I do?
 

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MrChips

Joined Oct 2, 2009
30,472
Welcome to AAC!

For every repair it is imperative to state the make and model of the unit. By doing so we might be able to locate the circuit diagram.
 

nsaspook

Joined Aug 27, 2009
12,782
That looks like normal pcb glue to stop components for vibrating due to sound. That looks simple to check for proper voltage.
 

wayneh

Joined Sep 9, 2010
17,493
I think one or both of those electrolytic capacitors leaked out. Lacking any other information, and knowing how often bad capacitors bring down electronics, I'd recommend just replacing them. It may or may not fix it, but anyway capacitors can fail with age and you'll be buying yourself more time if/when you do find the fix.
 

nsaspook

Joined Aug 27, 2009
12,782
I think one or both of those electrolytic capacitors leaked out. Lacking any other information, and knowing how often bad capacitors bring down electronics, I'd recommend just replacing them. It may or may not fix it, but anyway capacitors can fail with age and you'll be buying yourself more time if/when you do find the fix.
They may have leaked too and be bad but the glue is also on the connector. using glue is the typical cheap fix for vibrating (Subwoofer) parts issues for cheap imports.
 
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MisterBill2

Joined Jan 23, 2018
17,800
Can you tell me if it can be repaired and if so, what parts do I need? And for the context, my subwoofer started making a loud noise when is on. I opened it to look at the amplifier and noticed that there was a melted brown substance that I removed, you can still see the traces where it was. And now I see that some parts at the base are melted!? What can I do?
The amplifier appears to have three capacitors that have failed. Because all three failed, I suspect that othe parts, such as the rectifier diodes have failed and applied AC power to the capacitors, causing them to fail also. The black streak on the one smaller capacitor tells me that probably the diode next to it has failed.

So now a question: Do you have a multimeter that can be used for checking parts? And, are you skilled enough to unsolder failed parts from the circuit board without destroying it? A recent post showed a circuit board quite damaged by one who had no soldeing skill at all.
 

MisterBill2

Joined Jan 23, 2018
17,800
examine the four diodes near the wires from the power transformer D6, D7, D8 are what I can read. At least one of those looks damaged in the photo.
And if the amplifier suddenly stopped working and made a loud buzz in the speaker, clearly something went wrong. That might not all be glue that we see,
 
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