One of my earphones was not working. I troubleshooted to find out that there is a short-circuit in the audio-jack. Placed open the audio-jack terminal and soldered the wires again.
The earphones broke because the end of the audio-jack would rub against my body when I cycled. This is why while gluing everything back, I made sure that the earphones came out on the other side like shown below.
Needless to say, the earphones work perfectly!