Hello everybody.

I own Acer Ultrabook Swift 3 (Swift SF315-41) bought in April last year. These are the complete specs:

15,6'' FHD IPS screen
processor AMD Ryzen 5 2500U up to 3.6 GHz
8 GB DDR 4 RAM
1TB HDD + 128GB SSD
AMD Radeon Vega 8 graphic
Windows 2010 pre-installed.

So far, this proved to be my worst buying decision of all times.
Since I bought it, the sound is occasionally crackling when playing either music from MediaMonkey, or videos through Media Player Classic.
I first thought it was just the driver issue, and therefore didn't return it immediately. However after Windows updates, and manually updating all the drivers, the problem continued. 
To make things worse, this wasn't the only problem. The screen occasionally displays pictures as though they are RTG pictures, I don't know how to describe it exactly, so here's the picture:

You can see that the part where the sun is coming through the clouds is too light, and the same picture looks normal on my PC.
Also, occasionally the black dotted line started to appear inside my browser (Chrome) at random times.

I took the laptop to the authorized service in September. After a month, they said that they replaced the motherboard and that ''test was ok''. 
When I got home, all the problems were the same, only now the black dotted line started to appear more often in the browser. 

I was very frustrated because the vendor refused to refund me or give me another laptop since this one is obviously faulty and the authorized service is not capable of solving the problem.
Then, I decided to give it another go. I went through the same procedure and after a month the authorized service said that they replaced the speakers and the LCD and that ''test was ok''.

Happy, albeit skeptical, I took the laptop home, only to find that the problems are still exactly the same!
Except, there was no more black dotted line appearing in the browser (at least for now...). 

I obviously won't ever again buy an Acer product. I contacted their support for my country directly, and they didn't even bother answering to my polite inquiry.

So, what should I do now? The authorized service is obviously incompetent/unable to solve the problem, and the seller refuses to refund/replace the item.
I guess the only thing for me to do is try to solve it myself, so decided to give it a go here for ideas. 
My guess is that it could be a software issue, as 3 different parts of hardware were replaced (if we trust the ridicules from authorized service) with no results.