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Board repair for subwoofer

I have a 10 year old Martin Logan subwoofer which has had a chip or capacitor on a circuit board cease to function a few of times.  It seems that the amplifier chip overheats, and just pops.  It has done this three times despite having the sub sonic filter on my pre amplifier.  I don’t want  buy another entire replacement panel from Martin Logan, with the entire set of wires, connectors, circuit boards.  Does anyone know of a diagnosis and repair shop for a circuit board for audio electronics in the US? (I live in central Florida.)

drbond
erik_squires
17,543 posts
 

Those densely populated amp boards are hard to work with and diagnose.  If you knew exactly what part was going bad you could attempt a heat sink upgrade before installing the next one.  Otherwise, would you consider a third party plate amplifier? 

drbond OP
484 posts
 

After three boards in 5 years, replacing the board with a third party board wouldn’t be unreasonable.  It would just need to fit in the space of the old board, and I would need to find a way to attach it to the panel.  Which brands would you recommend for replacement amplifier circuit boards?  (The current board is a 850 W class D amplifier circuit board.)

gdaddy1
500 posts
 

How loud do you listen? Do you run demanding levels of EDM music or are you more geared to average listening levels or perhaps classical? Point is you may not need 850 watts of power and can save a bit of $ by downsizing. What size is the driver? What ohm?

drbond OP
484 posts
 

@gdaddy1 

I listen to only classical and jazz, and any acoustic music, but at realistic listening volumes.  I think that it’s a few vinyl records that I play that have a low rumble that causes the amplifier board of the subwoofers to detonate.  They are the Martin Logan Balanced Force 212 subwoofers, which have 2 12 inch woofers (drivers); RCA impedance is 10,000 ohms.

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