Headphone speaker stops working during repair: explanation?


2010-09-07 1:56 am
I was repairing the headphone of a friend of mine which started having output problems with the left speaker (solder connection coming loose). He tried to look at it himself some months ago and in the process removed the cable. I decided I would fix the headphone with a new cable.

Now, I'm not very experienced in this sort of stuff but I do know which connections to make and I can solder. I first tested the headphones by touching the new wire to the speaker and it worked. However, once I desoldered the solder on the left speaker it stopped working. Whatever I do I can't get it to work.

Is there any chance of fixing this or did I destroy one of the headphone speakers?


2008-01-08 11:51 pm
Is there any chance of fixing this or did I destroy one of the headphone speakers?

Maybe. The speaker has wires from the basket (where you make the cable connections) to the voice coil. These are generally very flexible and braided from many very thin strands (litz wire). When you solder on a new cable, depending on the exact arrangement, you can damage this connection to the voice coil. Whether it can be fixed is another matter.

The first thing is to determine whether the voice coil is shot. Take your new cable, connect it to a source, and try touching the litz wire with the 2 conductors as close as possible to the cone. If you get sound the voice coil is OK and the fix is comparatively easy. Work your way back up the litz wire checking that the sound is still there. The chances are that the litz wire was soldered to a tag on the other side of the basket from the input connections, and it dropped off when you heated the tag while soldering on the new cable.

Keep the soldering iron in contact with the job for as little time as possible when doing this kind of job. If it's necessary to repair a break in the litz wire, use as little solder as possible and don't let it fill up the wire and make it inflexible.

If the voice coil is shot or the connection has failed in an inaccessible place it's probably best to give up at that point, but somebody might care to disagree.