working on PCBs

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Re: working on PCBs

Postby (cjj) » Sun Apr 28, 2013 11:03 am

Sounds like some sort of bad connection somewhere. Since the voice coil on the speaker has to move, there are flexible wires between the speaker terminals and the cone/coil. These wires are the most likely to get damaged since they are moving around all the time.

The coil itself is less likely to get damaged since it's wound on a rigid form and often coated with lacquer or some other material to keep it firmly attached to the cone. While it's certainly possible that the wire in the voice coil can be damaged, it's less likely that it would be an intermittent connection due to the construction of the coil.

So, I'd check the small connecting wires between the terminals and the cone. Depending on where they might be broken, you may be able to fix them. If one broke near the terminals, you might be able to solder a short piece of wire between the terminal and the flexible wire. But in general, once you start having problems with the speaker itself, it gets difficult to repair 'em without specialized equipment...
I have NO idea what to do with those skinny stringed things... I'm just a bass player...
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Re: working on PCBs

Postby (chrisdski) » Sun Apr 28, 2013 1:01 pm

Meh- bad speaker. Pulled it again and now I get an open circuit. Battery does not move the cone. Being that it went from not working, to working, to not working there is something funky inside. I wiggled the wires from the connectors to the cone and couldn't get any signal to show. Oh well, off to a speaker replacement search.
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Re: working on PCBs

Postby (chrisdski) » Wed May 01, 2013 8:22 pm

popped in a new Eminence Alpha 15A and fired her up. Works great. I plan to donate to the local high school band dept. for their use (and mine when I sit in the pit band for local musicals- now i don't have to haul an amp ;-)

On another note- how hard is it to disassemble a speaker to look for an intermittent short? I have checked the wires until they disappear into the coil, so it has to be in there. It's a throw away speaker now so I figured I'd dissect it for knowledge and yucks.
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Re: working on PCBs

Postby (jps) » Wed May 01, 2013 9:57 pm

Slice around the perimeter of the cone and the spider and slowly pull it out from the frame to avoid damaging (cosmetically, at this point) the voice coil.
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