Dynaudio BM6A - Tweeters not working

[anneflyr]

Hi

I got two dynaudio BM6A. I had them in storage for a year. When I fired them up again the tweeter on one of them did not work. After an hours use the other tweeter also stopped working.

I open them up and measured the impedance on both the tweeters and the woofers. On the woofers I measured 5.4 ohm, but on the tweeters I did not get any reading on the ohm meter.

I have checked the relays. Them seem to work.

The resistor r94 close to the speaker connector and the relay on the circuitboard on both speakers have been very hot.

I think the tweeters are destroyed and needs replacement.

Why are they destroyed?

Will new tweeters get burned the moment I connect them?

https://dl.dropboxusercontent.com/u/12596575/bm6a_fail.jpg is a pic of the heated resistor.

 

[synthiaks]

B e100% sure that its not the relay anyway. Tweeters not working is a common problem with the Dyn's it's almost always the relay s

But looking at the pic this might be something else...
S

 

[anneflyr]

Thanks for taking a look!

I know that the relay is a common problem. But, I am not getting any reading on the ohmmeter on the tweeters. That leads me to think that they are destroyed.

 

[Apache5]

Test if there is some DC present on tweeter connection, without a tweeter...

 

[anneflyr]

There is no DC voltage on the tweeter connection.

 

[Gene Pink]

There is no DC voltage on the tweeter connection.

What about ultrasonics?

Sometimes wacky signal and speaker ground connections can interact and cause an electrical feedback. While the tweeter voice coil cooks and burns up, all you hear are dogs howling and bats flying into walls.

Gene

 

[anneflyr]

I have connected the woofer to the tweeters connections. I get a signal, but it is weak. The dog is quiet and no batsplatter on the walls.