Subwoofer AMP board is burnt. How to find suitable replacement?

[sidvee]

Yup. The capacitor has gone bad. Typically this is what mostly happens in SMPS failures. The stressed out electrolytic capacitor become bad leading to SMPS failure. Most likely the VIPer 12a chip is fine because these chips have built-in safety turn off. You will have to remove the glue carefully and remove the capacitor and put a capactor of the same microfarad value and with the same voltage or higher rating. The board will start operating once you replace the capacitor or the capacitor and the chip.

Replacing the capacitor is a very easy job. I'm sure there will be some FM in Hyderabad who can do this for you. Just a 2 min job. Removing the IC however requires a de-soldering hot air gun. Can be done with a soldering rod and desoldering braid too. But one has to be careful in not overheating and damaging the copper track on the PCB.

There is one more capacitor (smaller value) just above the IC in the photo above. The top is covered with glue. Remove the glue and confirm if that capacitor top surface is not bulging.

Was this subwoofer powered without a voltage stabilzer?

Thanks so much Mbhangui your guidance has been invaluable.
Will check out what can be done then. For now I will use an external amp., down the road I will look at the possibility of replacing these components. In regards to stabilizer, I always use one. I have a 3kva servo in my HT. I suspect it is just parts quality, when I opened the sub. I was quite disappointed with the quality of the board, wiring etc. Seems like a low budget Chinese assembly line product which it probably is with a SVS stamp. I am sure driver failure is not too far behind. I used lot of SVS products and initially some 15-18 years ago they had superb quality products when they first started. I got their first ported cylinder sub., and was blown away by what it could do. Those days only Velodyne and to some extend REL could compete albeit at a much higher price range. I replaced a REL with SVS at that time.
And it is just out of the 5 year warranty period.
Anyways I will use it as a spare with external amp., or get the board repaired later.
Cheers,
Sid

 

[mbhangui]

Thanks so much Mbhangui your guidance has been invaluable.
Will check out what can be done then. For now I will use an external amp., down the road I will look at the possibility of replacing these components. In regards to stabilizer, I always use one. I have a 3kva servo in my HT. I suspect it is just parts quality, when I opened the sub. I was quite disappointed with the quality of the board, wiring etc. Seems like a low budget Chinese assembly line product which it probably is with a SVS stamp. I am sure driver failure is not too far behind. I used lot of SVS products and initially some 15-18 years ago they had superb quality products when they first started. I got their first ported cylinder sub., and was blown away by what it could do. Those days only Velodyne and to some extend REL could compete albeit at a much higher price range. I replaced a REL with SVS at that time.
And it is just out of the 5 year warranty period.
Anyways I will use it as a spare with external amp., or get the board repaired later.
Cheers,
Sid

Using an external amp will be always better. Just that the crossover will have to be external. The SVS plate amp isn't worth more than Rs 5k. I think the crown xls class d amps, etc will do wonders. Also if you are doing cross over externally, the amp will be handling just a small band of the frequency spectrum. Bass does require more power and at demand. So if the amp has a good power supply you will be good. The svs plate amp hardly has a good capacitor bank. Here again, the new class of class D amps will do a better job than the internal plate amp. Probably you will never go back to repair and use the internal plate amp. You will probably loose the phase control. And if this performs better you could use the stereo amp to drive both the drivers using the left and right channel outputs. Why waste one channel of the stereo amp?

The glue job for vibration dampening looks like they use pigeons in their factory, fed with glue, to do their job sitting/shitting on the plate amp. They should have used indian pigeons for wider coverage.

EDIT: The Japs do it better. The put the glue at the bottom of the capacitors (at the base). Putting glue at the top of the capacitor will have zero effect to prevent the caps from dancing with the beats. Imagine a heavy truck heavier at the top, it will topple at the slightest sharp turn. This is physics. My Yamaha avr has it at the bottom. Even my Indian made Shanti power supply has this done better by layering the entire bottom with meltable glue, in fact so perfect that no components can vibrate.

 

[ZzZzZ]

The glue job for vibration dampening looks like they use pigeons in their factory, fed with glue, to do their job sitting/shitting on the plate amp. They should have used indian pigeons for wider coverage.

ROFL

 

[sidvee]

Anyways I will use it as a spare with external amp., or get the board repaired later.
Cheers,
Sid

I hooked up the sub to my Sabaj A20a, which has bridging capability and also a built in crossover (which I am not using, as I am using the x-over from my receiver). With the amp. bridged, everything sounds the same, as it was with the plate amp. functioning. I am glad I did this instead of just dumping the sub. or ordering another plate amp. which would have costed me at-least $500-$600 delivered. So will continue to use this solution for a while, till the time the driver fails.
Cheers,
Sid

 

[rwnano]

Which terminal did you use on the Sabaj to connect your SubWoofer? Left or Right...I saw your Sabaj on Amazon, it has two terminals, right?

https://www.amazon.com/Version-Amplifier-MA5332M-Provide-Bluetooth/dp/B0B2QX9LFR

 

[sidvee]

Which terminal did you use on the Sabaj to connect your SubWoofer? Left or Right...I saw your Sabaj on Amazon, it has two terminals, right?

https://www.amazon.com/Version-Amplifier-MA5332M-Provide-Bluetooth/dp/B0B2QX9LFR

You can bridge it by setting the stereo/BTL switch to BTL, and then have to use the R RCA terminal that is labelled as BTL to connect to sub out of receiver. Then you have to connect speaker wires to the sub. using +ve terminal of the left set of speaker connections and -ve terminal of the right set of speaker connections. The 6th photo in your link shows this.
Cheers,
Sid