The Left side of my headphone is not working
you remove the paddingyou remove 4 screwyou use a very small screwdriver to pry the pivot point to be able to gently slide the speaker off.you will see that the speaker wires for the left speakers are no more soldered.
pull them a little bit to have more room to workuse a soldering iron to fix them back respecting the positive/negative connection(red+/black-)
Voila! Worked for me.
Sorry for bad english"
@joshanjoy there is a crossover cable from one driver (speaker) to the other, check that out. Use a multimeter and check for continuity. Also check the solder connections on the driver (speaker) make sure the cable is still soldered on.