[SOLVED] Fixing stereo headphones - right speaker not producing sound

[yonyz]

Hi,

I have a pair of Audio Technica ATH-M50 headphones.
The right speaker died about 2 years ago.
I recently bought a new pair of elements, for both sides (didn't like the idea of having one old element and one new element), soldered both according to notes I took and photos I found on the web, but the (new) right speaker still does not make sound.

I checked for short circuits - there are none as far as I can tell by checking with a multimeter.

I checked that the right and left elements are connected, that is, that the cable that goes from the left to the right element conducts electricity - it does (I properly removed the enamel coating).

Here's how I soldered the left element:
https://i48.tinypic.com/2nty4j4.jpg

Here's the right one (same photo, edited accordingly):
https://i49.tinypic.com/2rqkda8.jpg

What am I doing wrong?
I checked each element separately (by connecting each to the main RED, GREEN, BLACK wires that are connected to the stereo plug - they both work.
But for some reason, when the right element is connected to the left element via two litz wires (red and copper-colored), the right element does not product sound.

Please advise.

 

[Genovator]

I checked that the right and left elements are connected, that is, that the cable that goes from the left to the right element conducts electricity - it does (I properly removed the enamel coating).

Can you show in the image which wires goes from left piece to right
ATH-M50 is a stereo headphone. So obviously it is getting its Right element feed from the audio jack directly. Have you checked the conductivity from jack to both left and right piece individually???? Does both get voltage from the jack??

 

[alexan_e]

If I'm not mistaking the black and green wires are shorted because they are connected to the same pad, if so one side is shorted and will not operate.

My guess is that only the speaker of your second image works because it is not shorted and gets the signal from black-red.

 

[yonyz]

Can you show in the image which wires goes from left piece to right

Yes, circled in blue here:
https://i47.tinypic.com/10gbwg6.jpg

ATH-M50 is a stereo headphone. So obviously it is getting its Right element feed from the audio jack directly. Have you checked the conductivity from jack to both left and right piece individually???? Does both get voltage from the jack??

The ATH M50 only have one big cable going from the stereo plug to the left speaker. There isn't a cable/wire that goes directly from the stereo plug to the right speaker. The right speaker gets its feed from the left speaker, via the cable (with two litz wires) that is circled in blue in the image above.

If I'm not mistaking the black and green wires are shorted because they are connected to the same pad, if so one side is shorted and will not operate.

The close together black and green wires (the ones separated by a middle red wire) are indeed connected to the same pad, but that's normal. The black wire is ground and the green is the left speaker signal.
The red wire between them is the right speaker signal, and it's connected to the right speaker via the two litz wires that can be seen on the left of both images of the original post.

My guess is that only the speaker of your second image works because it is not shorted and gets the signal from black-red.

Actually it's the speaker in the first image that works. The second image shows the right speaker which only has two litz wires soldered to it, and it does not work.

I checked with a multimeter and the stereo plug is connected (directly or indirectly, depends to which speaker) to both the left and right speakers. I do not know why the right speaker doesn't produce sound as it seems like it does get a signal.

 

[alexan_e]

So the green wire (left channel) is shorted with the ground and you consider this normal!
That's a first for me.

When you have left and right signal with reference to the ground how does it make sense to short any of the channels with the ground?

 

[yonyz]

I'm not saying it's normal, but that's what I saw in pictures. In fact I'm glad to know I'm wrong, cause that means that maybe there's something I can do to fix the problem.
Where would you solder the green wire instead, or the ground (black) wire?

 

[alexan_e]

How did you figure the way to solder the wires?
Did your original headphones have the exact same units wired this way?

 

[yonyz]

Yeah, though I might've forgotten some small detail, but I googled for photos of it and the first photo of the original post is what I found. I figured the right speaker is soldered the same way.

 

[alexan_e]

Connect the ground and green to one side and connect the red color directly to the cable (no pcd) with the ground soldered on the pad



Check if it works

 

[yonyz]

Totally confused.
Mind guiding me using the first photo I provided?

 

[alexan_e]

This is from your first photo, disconnect the green wire and the insulated red from the pcb and connect them together like I did with the blue line

 

[yonyz]

Connect them together to what?

 

[alexan_e]

one wire comes from the amplifier and the other goes to the speaker so connect them together, I don't understand what you find confusing

 

[Genovator]

You can do many trials....
1. Connect both red and green together. There is no harm. It will convert your stereo headphone to mono. This time, either both speakers should work or no one should work.
2. Do not connect the speakers with any source. Check the conductivity of red & black, green & black by a multimeter for both the speakers. Maybe this time also your right piece is damaged(coincidence).
3. Check conductivity of the black cable (blue circle) which connects both the speakers. (both red and yellow wires)

 

[yonyz]

one wire comes from the amplifier and the other goes to the speaker so connect them together, I don't understand what you find confusing

What amplifier?? And you suggest I solder these two wires together and tuck them somewhere inside the speaker enclosure, without soldering them to the pcb? Sounds weird.

I did some trial and error.
I didn't touch the two litz wires, I kept them soldered where they were (as in the pictures above). I played with the green and red wires only.
When both the red and green are connected to where the green is connected in the pictures, there's sound coming from the left speaker only.
When both the red and green are connected to where the red is connected in the pictures, there's no sound at all in both speakers - that's the middle "pad" of the three red, green and black wires. Maybe this middle pad is for the ground... Gonna try that.

 

[Genovator]

Doesn't matter. Middle pad is a carrier. You can alter it with the ground (black) wire. See if it works. Check whether the black wire which goes from left to right speaker is ok or not???

 

[yonyz]

Finished my little experiment, same result, right speaker is not working, left speaker is working.
Genovator, the black wire works, and the right speaker itself works too.

 

[alexan_e]

What amplifier?? And you suggest I solder these two wires together and tuck them somewhere inside the speaker enclosure, without soldering them to the pcb? Sounds weird.

There is an amplifying stage that drives the headphone output , do you find that strange?

To me you have two options , connect wires as you do now shorting the ground with the left channel or make a floating connection of the left channel to the wire going to the other speaker, apparently you think that shorting the left channel is the normal solution and avoiding it is the strange one.
You could at least try it to see if it works first.

 

[Genovator]

Both speakers are good, the carrier wire from left to right piece is good. Then I can see only one possibility for now....

When both the red and green are connected to where the green is connected in the pictures, there's sound coming from the left speaker only.
When both the red and green are connected to where the red is connected in the pictures, there's no sound at all in both speakers

See whether the green or red is anyhow shorted with ground?
Try soldering the red in place of green, and green in place of red.

One thing you haven't replied. Whether the green and red wires conducts voltage from its audio jack. Sometime wires torn out from the jack's nob.

 

[alexan_e]

Both speakers are good, the carrier wire from left to right piece is good. Then I can see only one possibility for now....

See whether the green or red is anyhow shorted with ground?

We ha established there is a short in post #3-#4

The close together black and green wires (the ones separated by a middle red wire) are indeed connected to the same pad, but that's normal. The black wire is ground and the green is the left speaker signal.
The red wire between them is the right speaker signal, and it's connected to the right speaker via the two litz wires that can be seen on the left of both images of the original post.