Macbook pro 2017 headphone jack broken - noise

Hello

I think my audio card or headphone port is broken :(

I have a macbook pro 15inch 2017 (4000€) and a few months ago i made a post about my broken internal speakers. I took it to Switch (official apple seller) and they fixed it for free (because it was still in 2years warranty) They replaced the top plate (they also replaced the trackpad, keyboard, touchbar and speakers. Because this is all one piece) So, Thanks Apple, appreciate it.

Problem?

Now, 3months later, i noticed a silent noise coming out of my speakers. At first i thought it was due to my old speakers. Because that's normal... So i ignored it. Last week, during a videocall, my friends told me that they heard a silent but disturbing noise coming from my computer. I used a headphone with built in mic.

They didn't hear any noise when i used the built in mic from my macbook itself or my earpods. The problem is only here when i use a mic that is plugged into the headphone jack.

To test this problem even more... I took a bluetooth speaker and connected it with a cable. And also here, I heard a silent but disturbing noise. I tried it without cable and the noise was gone.

Conclusion?

Everything that passes through the headphone jack has a silent but disturbing noise.

Does that mean that my headphone jack is broken? Or maybe the soundcard which is built in the macbook.

How i hope to solve it?

I might consider to buy studio speakers with an external professional sound card (scarlett audio interface)

Because, they will send sound via usb instead of headphone jack. So i guess that'll solve the noise issue.

But of course i want to know how this problem is even possible, and if they can solve this?

I also noticed blue spots on my macbook screen when i recieved it back. It seems like they put a lot of pressure on the screen during the replacement. (I did some research about that, and you guys said that i should return it back to the store.)

It's sad that the first problem caused 2 new ones :(

I know that if you buy something expensive, the replacement costs are expensive too.

But when you pay over 4000€ for a device, i expect it to work without any issues.

I completely understand that the replacement costs for broken parts is expensive (if you break it yourself)

But for things like this i think it's ridiculous to pay a huge amount of money. And i think that everybody here is very careful with his/hers computer. If you buy a computer that is this expensive, you take care of it as your own baby. So that being said... I hope the problem will be gone if i have that external audio interface connected to it. Because my 2y warranty is over now.

Thank you

Emile

Belgium