Got a weird problem with my brother's earphones.
The jack has some round scratches due to heavy use and sometimes the left earpiece just stops working with his smartphone, no matter how much you try to move it and correct it.
On some devices the left side won't work, including the laptop. But once you plug it in another device (for example an ipad) it will suddenly work flawlessly again!
The strange part is, when you plug it to his phone afterwards, both sides will work just fine again not matter how much you move it, same for the laptop... Then after a while the problem occurs again... and we have to plug them in the ipad again to fix that issue... this started just recently
It's still under warranty, the problem is that they work fine with some devices
Any ideas what could be the problem? the scratches aren't that bad at all and there's no static.