Question earbuds connected to laptop audio jack give humming sound

Dec 18, 2020
Hello, new member here, have already read through a couple posts and while helpful, my issue has a specific backstory.

I am using a Lenovo X1 Carbon Gen 3 2015 (20BS). A few months ago, I spilled some mineral water on my laptop while it was working and the keyboard + sound output stopped working. However, the audio when connected from my bluetooth airbuds worked as normal.

A few days ago, I finally receieved my keyboard replacement from eBay and installed the new keyboard. The keyboard works fine and suprisingly, my output audio works now! The process I followed was as below:

The process involved taking off nearly every component (motherboard, USB ports, audio jack) to reach the keyboard.

All seemed well, however, when I put my earphones in the audio jack, I noticed a "humming" sound. Per reading threads here and my past experience this seems to be a grounding issue- i.e. something is interfering. Further, the humming only occurs when my laptop is connected to its charger, removing it removes the humming.

I tried to open the laptop twice and add electrical tape to isolate the audio jack wire(wafer thin and wide connection) connecting to the motherboard. This seemed to reduce the humming by ~50-60%.

Its worth noting that this is a 5-year old laptop, so it should be expected, and to tell the truth, I'm not sure if this issue existed before I replaced the keyboard since I generally used my bluetooth earbuds.

Another thing, when I was removing the components, a lot of connections were "stuck" pretty hard and I tried my best not to break anything. The wire connecting the audio jack to the motherboard is slightly bent.

I've also checked to see if the issue is with my earphones, I've tried them on other laptops and they work fine.

Sorry for the long winded post, but I wanted to give as much information as it might relate to why I am facing this problem.

My next thoughts are opening my laptop again, but this time removing all the connections to the motherboard and re-connecting them. Another step could be removing the motherboard (this is where the adapter connects to on the side) and replacing it. However, I really do not want to "potentially" harm my laptop further as I see myself using it for a while longer (no other complaints).

What do you guys think? Perhaps I can get used to the sound. I also know there are accessories you can add to the end of your earphone - maybe this is an option. Or I can try using a usb earphone.

Thank you for taking the time to read this post.