MBP 2017, Horizontal lines display. Flickering, buzzing noise.

"Well not good ;-{

The T-CON is in trouble this is the part that sits inside of the main case. It’s located is a hotter part of the system between the two heat transfer fins of the heat sink. So any blockage in the vents (sides and back) can cause things to overheat.

To add to this running heavy video work can saturate the systems cooling system. I do strongly recommend getting a good thermal management app like TG Pro

I’m not sure if you also have a display issue as well.

While you likely didn’t bang the system given what you stated. You may have caused a problem during your cleaning of your displays screen. I’ve seen a few systems damaged by cleaning liquid dripping down into the electrical connections. This is most of the time due to spraying the cleaner onto the glass and then wiping the screen. The better (safer) way is to spray the towel/cloth and then wiping the screen.

In either case the solution is the same replacing the display assembly MacBook Pro 15"" Retina (Late 2016-2017) Display Assembly and here’s the guide MacBook Pro 15"" Touch Bar 2017 Screen Replacement"

It appears to be an issue with the built in display.