Martin Logan Low Pass / Backplate Board

[m_shiva2003]

One of My Martin Logan Vantage speaker is suddenly stopped working. I can hear only sound from panel but no bass from woofer. I swapped Woofer, circuit boards from working speaker to non working, and found that Low Pass Circuit board "BCFS9LPd" is bad (as shown in the picture). Can someone please advise what may be issue and how to get it fixed ?


Thanks in advance

 

[Leporello]

Anyone have a schematic? Someone is going to have to trace the signal through the board and see where it stops, which is virtually impossible on the basis of one photo. Or else, buy a new board, if ML still makes it.

A tech still has access to the other, working board, to "comparison shop", which can be helpful.

 

[m_shiva2003]

Thanks Leporello. I already contacted ML and they are not making those boards anymore unfortunately.

 

[Robert D]

Thanks Leporello. I already contacted ML and they are not making those boards anymore unfortunately.

I wonder, is that where the amp is located? Maybe you can find an aftermarket if its just the amp.

 

[Brandon Hartwick]

Did you request a crossover schematic from ML tech support? Usually they're pretty helpful about giving that stuff out.

 

[Brandon Hartwick]

Alternatively, if you are unable to find a board or fix that one you could pickup a pro audio amp with electronic X-overs and just bypass the board completely.

 

[m_shiva2003]

Alternatively, if you are unable to find a board or fix that one you could pickup a pro audio amp with electronic X-overs and just bypass the board completely.

I have schematic which i received from ML for this low pass board. I am not sure how to check and what tools to use find the issue ..

 

[Brandon Hartwick]

I have schematic which i received from ML for this low pass board. I am not sure how to check and what tools to use find the issue ..

Depends, if something in the amp is broken that's likely out of most people's ability to fix outside of an electronics tech. Crossover components can be tested with a volt meter along with any connections inside the speaker.

I find it kinda ridiculous that Martin Logan no longer sells boards for the Vantage, that speaker isn't even that old. If you're not confident in troubleshooting I'd highly recommend just bypassing the whole amp and woofer crossover at this point.

 

[Brandon Hartwick]

Also post up the schematic so the information will be available to others.

 

[Robert D]

Depends, if something in the amp is broken that's likely out of most people's ability to fix outside of an electronics tech. Crossover components can be tested with a volt meter along with any connections inside the speaker.

I find it kinda ridiculous that Martin Logan no longer sells boards for the Vantage, that speaker isn't even that old. If you're not confident in troubleshooting I'd highly recommend just bypassing the whole amp and woofer crossover at this point.

That sounds like the easiest way to deal with it. Everyone on here says that external crossovers are superior anyhow, might as well just do that. Any amp can drive the woofer too, and probably be higher quality.

 

[m_shiva2003]

Also post up the schematic so the information will be available to others.

 

[Brandon Hartwick]

This isn't an amplifier board, it's crossover and EQ. It's tough to say exactly what's wrong with it.