A while back I purchased a pair of AKG 7XX Reference Headphones off of Massdrop. The right ear is no longer producing any sound. I found this article on reddit which allowed me to determine that the cause was a broken connection in the right ear. The picture below shows what I am talking about.



So obviously the solution is to solder the wire to complete the connection; however, I have never soldered anything in my life and I am terrified of damaging my headphones. Could someone give me some advice on things to look out for in this particular soldering scenario? For example, what tip to use, what temp to use, easy mistakes to look out for etc.

 

Welcome to AAC!

The safest thing would be to have someone else solder it for you.

If you're determined to do it, get a small conical tip, 700F. Use 63/37 solder as it's eutectic and is less likely to give you a cold joint. Put rosin flux on the wire and tin it. Hold the tinned wire against where it needs to be attached and apply enough heat (to wire and contact) to reflow (melt) the solder, remove the iron and hold the joint still until the solder cools (you can blow on it to speed it up).

Practice on something unimportant to get your technique and timing down.

700F is hot enough to melt plastic quickly.

 

Practice on something unimportant to get your technique and timing down.

What would you recommend practicing on?

I was thinking of just getting some wires, soldering them together, and testing for continuity.

 

Just get a small soldering iron kit from a discount tool store, between 10 and 30 watts.
https://www.harborfreight.com/elect...30-watt-lightweight-soldering-iron-69060.html
https://www.thesource.ca/en-ca/smar...r-tools/vital-5-piece-soldering-kit/p/6412031
Or pay someone in pizza/beer or whatever to do it for you.

Practice on wires, the terminals on speakers in a junked radio. Maybe even buy a simple kit on ebay that requires soldering. Watch some Youtubes.

 

What would you recommend practicing on?

I was thinking of just getting some wires, soldering them together, and testing for continuity.

Sorry for the delayed response. I must have missed the notice or forgot about it.

Using wires should be sufficient. I'd be more concerned about getting enough heat to reflow the solder while not melting any plastic parts. If you use 63/37 solder, you have less chance of getting a cold joint. For your purposes, a good joint would give you more mechanical support.

 

Firstly, do you have a soldering iron? If yes, show us a photo and tell us the wattage.

 

My 2 cents,
(@Mistah_K )
Also, in order to try to estimate the risk:
In your picture, I see the red wire is disconnected. I also see a blob of solder below it.
I assume that is where the wire needs to be connected to.
Can you tell us what kind of material is below that blob of solder? I assume it is a contact surface, but is it in plastic or what?

A common best practice is to "tin" the wire first by melting some solder on it.
Then put the wire on the blob of solder on the contact surface and touch it with the soldering iron while applying a bit of extra solder to help the heat transfer. I know... you could use a few extra hands. The solder on the wire should join the blob of solder on the contact surface. Remove the soldering iron while ensuring the wire does not move.
If the solder turns matt (not shiny), then you have a "cold weld". That is not good
If the solder remains glossy, you may have a good connection.

Solder contains flux to make it flow when it is hot. This flux "burns" when it makes the solder flow. If you re-heat old solder, it may not flow well because it does no longer contain any flux. You could add flux, or typically just a bit a fresh solder my do it as well

hope this helps,
chrisV

 

Firstly, do you have a soldering iron? If yes, show us a photo and tell us the wattage.

Yes. I have this soldering iron.

Can you tell us what kind of material is below that blob of solder? I assume it is a contact surface, but is it in plastic or what?

Not sure I understand what you are asking. The blob is on the tip of a metallic pin. The headphone itself appears to be made from a durable plastic material.

I read an article online about repairing these headphones. The guy said you need to be really careful otherwise you might end up damaging your headphones. I suppose this repair may take a bit of finesse. Or perhaps some tools to help me hold it in place while I am soldering.