Chosen Solution
Replaced a dead HDD with an SSD, using iFixit-tools with the wheel to open. Everything went fine, have done a few of these before. Just as Im about to power down and put the new adhesive strips on I notice a black dot/spot/speck in the middle of the screen. Its not at the pixel layer, it moves around when changing angles and is a few mm behind the pixels/display. Is it possible for something, for example a piece of the old adhesive tape crumbled up to fall behind the metal from up top? I see people getting dust in the bottom corners of their 5k iMacs that has gotten in between the layers so it seems to be possible for things to enter behind the metal plate. Do you think it would be possible to follow this tutorial to get behind and clean if it actually is some kind of dirt? https://www.youtube.com/watch?v=Wul8dN4f… Attaching some photos and video, not the best but you can see the black dot inside the green and orange icon respectively.
Sadly it does look like something got in. The shifting is do to parallax as the piece of dirt is stuck on the back side of the cover glass so as you shift your point of sight the piece of dirt appears to move when in fact its not.
