Repair of the Fiio E17 portable DAC/Amp headphone jack
May 5, 2015 at 10:47 PM Thread Starter Post #1 of 3

Kodhifi

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A friend at work had an E17 that suffered it's 2nd headphone jack failure. He had already had it repaired once and the jack only lasted a few months before the new one started cutting out in the left channel, then no sound at all. He asked me if I could solder a new jack on for him since I have a Weller temperature controlled solder station and a little experience.
 
When I got the cover off I found the problem and unfortunately it wasn't just the audio jack. The circuit trace had broken off the board! I am not super familiar with the headphone jack problems on this unit but apparently it's been a big issue for the community so I wanted to document and take some photos of the repair process. Additionally I have an easy solution to preemptively prevent the problem, or repeat it from re-occurring.
 
From the look of this unit, the previous repair was unsoldering the original jack, and soldering a new one on. That fixed the broken jack but because the main issue is a design defect in that the jack is only supported by a few solder contacts, this resulted in the new problem of the circuit trace breaking off the board. For those not familiar with circuit boards, the trace is the actual metal foil that connects components together on the board. If it pulls up you are basically SOL because the board is damaged.
 
 
The repair:
With nothing to solder the new jack to for the left channel I went ahead and unsoldered the original jack and soldered in the replacement as best I could. It looks like the left and right audio channels are on the battery side of the connector, top for right, bottom for left. Ground is midway on the side of the jack. The other 4 solder points do not go to the headphone and my guess is they are the "support" that keeps the jack glued to the board. This is part of the problem as the solder points are thin little pieces of almost foil like metal. Not structurally strong enough to take the force of jack insertion.
 
After this was done I verified I could get audio and as I suspected there was no left channel. In order to bypass the broken board, I needed to find another component that I could jumper to in order to get a left audio signal. This wasn't a problem since the output capacitors and other components were surface mount. I simply grabbed a jumper wire, held it to the left audio input pin, and started touching components close to the broken trace. I was able to get a clean audio signal on one of the surface components about 2mm from the solder point. Too far to solder. I decided to make a jumper out of a household metal staple. I bent it straight and cut it to about 4mm in length. Using ceramic tweezers I soldered it to the headphone jack and the other end to the component that was providing audio. The first attempt failed when I tried to reinforce the jack so I had to try again. Make sure that you get a good solder contact, use flux and preheat the joint before adding solder.
 
 
 
The improvement to reinforce the headphone jack:
 
After I jury rigged a jumper to restore the audio to both channels I needed a way to support the entire headphone jack or the problem was just going to come back in a few weeks or months. The solution I went with is a product called Instamorph. It is a thermoset plastic that can be worked with the hands and sets in a few minutes into a very hard, very strong plastic. I used a few grams and dropped them into a hot coffee cup of water. I then heated the water with a butane torch until it was boiling. I wanted it as hot as possible in order to get into every nook and cranny. After working the wad of plastic until it was a transparent cube about the size of a sugar cube, I checked my soldering work one last time, and then packed it onto and around the headphone jack. There is a screw post above and to the right of the headphone jack, I packed some up there to hook into the case. The only thing behind the jack is the battery and that is too easy to move so went with surface grip and that hook. The end result was a wad of thermo plastic that covered the entire jack and about 3mm of board all the way around. I made it purposefully thicker than necessary so that when I put the cover back on, it would squish it into the rest of the voids and bond to the cover. This resulted in a little bit of instamorph flash pushing out of the side of the enclosure. I just cut that off by running a scalpel along the seam. I then tightened the enclosure down snug and left it to cool.
 
This has several advantages over hot glue in that the plastic is much cooler when you set it so it is less likely to damage anything form heat. It is also much stronger. Hot glue is great at adhering things together, not so much at being a structural support.
 
 
 
 
 
I am happy to say that the surgery was a complete success. From the outside it is impossible to tell that this E17 has been modified. The headphone jack works like a charm and if it should ever misbehave again, it will be tough to get the instamorph off, but not impossible. It makes a light bond to materials but it is not a glue. It can be carefully worked apart. Hopefully it never comes to that though. If this is a concern for you then you can spray or rub a little bit of silicon lubricant over the area so that it doesn't adhere too well.
 
 
Here are the pics. Note, because I had a limited time to work the Instamorph before it set, and I had to get the lid on, I do not have a photo of it but I created an image to show how it's used.
 

 

 

 

 
Sep 3, 2015 at 6:51 AM Post #2 of 3

alwaysblur

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Amazing repair. Unfortunately my E17 headphone jack has suffered the same fate, although I've had it for 2-3 years. Been loose for months and now its snapped clean off. Was using it with a 6.3 to 3.5mm adaptor, hardly moved it around as ended up using only for my desktop.
 
Wish I had your skills! Only done basic soldering, nothing so fiddly. No more Fiio portable products for me!
 
May 31, 2016 at 8:51 PM Post #3 of 3

TheManimal

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I am going to try this.  Learn some new skills I will!  Thank you very much for writing it in a manor many of us can actually as first timers attempts with some level of confidence.  
 
Annoying the jack was installed the way it was, especially given the cost of the unit.  
 
Thanks again Kodhifi!  
 
TheManimal
 

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