White dots ONLY on videos (youtube, etc), after techs cleaning.

[Carolina_2]

screenshot
https://lh3.googleusercontent.com/-tKGdYyxYIxg/WeZbQHv6wcI/AAAAAAAAEkk/2p187Hgmqgk7R3pSJVPT4If_janTu-RxwCL0BGAYYCw/h768/2017-10-17.png
can you see it? my friend says there it's nothing wrong there, but i can see it and screenshot it as well..

those white pixelated stripes only show on white backgrounds inside any and only videos

I only noticed this after i send it to a tech where they fixed an overheating and shutting down problem and that caused temperatures to go almost to 90º while doing almost anything - now they are around 50º the most of the time.

what could this be i know there's something going on with gpu since i also have another issue with a sort of burn in that shows/fades according to how much heavy stuff i run, but that's been like that for a year.
So what about this white dots new thing? Any insights?

 

[hang-the-9]

Don't see anything odd in he screenshot, you may want to circle specific issues you are seeing in the screenshot.

Need to list full system specs, troubleshooting without knowing anything about the system is no good.

If you had high temps, it can easily have damaged the video card which would cause image artifacts. Did you try with another monitor and video cable?