Over the course of the series, we saw Data worked on pretty extensively. Chips inserted, plugged into computer interfaces, even an iron filing removed! Trouble is, all the various openings show seem to contradict one another over time. Has anyone ever illustrated an image of his head, tracing all the portrayed openings? Seems his whole head would be criss-crossed with contradictory etch-a-sketch type lines!
I was under the impression that they often used only a small number of possible connections, to save on the FX budget, but I never paid close attention.
There are definitely a few questionable overlaps, but you just gotta shrug and go with it. (Also, he may alter or upgrade his ports over time.)
Weren't most of the skull access panels hidden by his hair/wig? Perhaps a different wig is attached after or during modifications.
I remember not giving it much thought at all until (I think) the episode Brothers, when Dr. Soong opened a panel in either Data or Lore's face. Bear in mind I haven't seen it in years, and don't own any of the series and can't check, but I remember the face panel as being a (for lack of a better description) weird Texas-ey shaped thing that had to have contradicted earlier depictions. Seems like they could have used something in-stock, which would have been both consistent...and cheaper! Mind you, I'm not a micro-continuity person, and I never lost sleep over this stuff, but for some reason it crossed my mind again. Also, now I'm wondering if that kind of Data-stuff fell under the jurisdiction of makeup, or props?
It's the 24th century. His skin is made of some nano material. He has flexible access panels that are created and open up whereever they are currently needed.
If you can overlook the fact that his access panels appear to be outside the contour of his head, you can overlook inconsistencies in the lines.
Data's head might be a mosaic of little plates, and you open as big an opening as you need to in order to access a section of his interior. So the access panel seen in say Brothers, would be composed of dozens of the small plates, all swung open as one.
Sort of like those old tailgate doors on station wagons, where the door can open either on a side hinge or downward.