XPS 13 9360 audio jack crackling

Hello,

One or two months ago i started noticing that audio played over my headphone jack (headphones i.e.) play a crackling sound when the laptop is connected to the charger. In the meantime the crackling, noisy sound also occurs when the laptop is running on battery and gets stronger, to the point that i cant really do my work properly as im using the laptop for a study where people have to listen to certain kinds of music and rate their experience. The built in speakers work just fine.

I just had time to clear up things and wanted to contact support for a replacement but noticed that my warranty ran out like 10 days ago.. If dell support reads this: Is there a way to extend my warranty or any way to still accept a replacement out of good will? I really like the laptop besides the audio problem and dont wanna sell it in this condition either. 

Or are there replacement parts, or a way to clear the jack or something? It might be caused by some internal short circuit or interference of some part that affects the audio jack, maybe it can be opened and certain parts isolated..

Best regards,

Matthias