My Koss Porta Pro right driver seems to be dying. Any clues what could be a potential cause?

[Not_Daijoubu]

I just need some direction on how to pin point the problem. If I can help it, I don’t want to have to claim warranty yet. Even if I have to get it repaired/replaced, I’d like to know what the reason is.

So every now and then, when I plug the headphones in, audio playback only occurs in the left channel. If I do some fiddling, the right side works again. The work perfectly for the duration I use them, not cutting out in operation. Until the next rare occasion that they stop working when I plug them in.

I suspect it is not wire because:

1. soldering into driver seems fine. No obvious breaks elsewhere either
2. Giving the driver an impact (i.e. snapping them off and on the headband or pulling the headband back and letting the driver slap my ear) seems to kick it back to life.
3. At least from outer appearances, 3.5mm is still intact without any signs of wear. Strain relief is still straight. Wiggling it in a jack doesn’t change anything.

Some additional info -
I did do 5 Kramer hole in the grille. Was careful not to let debris get to the drivers, but potentially and issue? Nothing macroscophic.

[Jose_G]

@Not_Daijoubu

I did do 5 Kramer hole in the grille. Was careful not to let debris get to the drivers, but potentially and issue? Nothing macroscophic.

it’s def possible, it’s also possible that the cable is just getting janky since that has happened to me with the ksc75

[Not_Daijoubu]

I think I figured it out. Opened the plastic cover (rip one of the pins) and the two microwires were touching. The red insulated one has a bit of an exposed section (marked in the image) and that was probably causing a short. I’m guessing when I banged on the driver, the impact would shift the two contact points apart.

Been two days since I moved the wires away from each other and so far no issues.