My son bought these about a month and half ago and they stopped working. I narrowed it down to the mini jack.
Things you will need:
Helping Hands for soldering
Razor (or sharp knife)
Heat shrink tubing
Straight or angled pick
Small Phillips head screw driver
The Original Super Glue (Cyanoacrylate)
Step 1: Cushion Removal
I started by pulling back the blue padded cushion back. Simply pinch the cushion and pull the cushion back. This gave me access to the 3 phillips head screws.
Step 2: Wire Color Verification
After removing the 3 screws, I was able to see which colored wire went to the right-side headphone.
Step 3: Wire Preparation
Next, I cut the mini jack wire 1/2" above the end of the mini jack. I stripped the insulation back and pulled the 3 wires out (Ground, Green, Red). Cut the wires in a staggered pattern, ground wire longest, red wire shorter, and the green wire shortest. Use a razor to strip the insulation off the wires. It may not seem like it, but the green, red, and even copper color is insulation, its Acrylic. Use the razor to carefully peel off the acrylic insulation off the three tips of the wires, including the ground wire. The mini jack casing needed to be hollowed out, I used a 45 degree pick to remove any insulation inside the casing. (Note: keep the metal casing on the wire down stream from your bare wires. If your solder joint is too big, you may not be able to slip it on later).
Step 4: 3.5mm Jack Soldering
Now that you have bare wired tips, solder them to the 3.5mm jack.
Step 5: Heatshrink the Soldering Point
After soldering, I insulated the wires with three overlapping strips of heat shrink tubbing. One is more than enough, but I wanted to have a tight fit when the joint was inserted into the metal tube (next step).
Step 6: Casing Installation & Finished
Next, we will pull the metal casing over the solder joint. But first, I copiously applied the Original Super Glue (Cyanoacrylate) over the heat shrink in order to keep the casing from slipping off easily. After you apply the glue over the heatshrink, slide the casing over heat shrink and hold in place for a few minutes while drying. My son, now has a set of working head phones, love you bud.