If you're curious to see what a brand new Canon 5D Mark IV looks like on the inside, here is you chance. LensRentals has already done one of their popular teardown articles on the new camera, and taken one apart before most people who preordered it even received it yet. This post obviously won't help your photography in anyway, but it sure is interesting and fun!
LensRentals, and myself included, would not expect to see much difference when taking the camera apart, besides maybe seeing some new processor chips, as it looks almost identical to the now older 5D Mark III on the outside.
However taking this new model apart, was a little different for them. They mention that disassembly is usually the same, as you take out the screws on a panel, and than just repeat on another side of the body, until the outer shell is gone. This new model though, now has has plastic pegs and latches inside, that interlock and hold the shell together more. They feel that these new pieces in the assembly, make the body stronger, make the seals tighter, and possibly even more resistant to water.
They also discovered more complicated cables going to and from the LCD display, and assume this is there to run the new touch screen feature on the 5D Mark IV, but otherwise it is what they have seen before in previous models. Also, most of the cables throughout the entire body are thicker and more elaborate overall, than they were in the earlier Mark III.
The only real downer they say they discovered is the USB and HDMI ports being soldered to the main board, instead of having separate boards like the flash sync and audio ports do. LensRentals says they see a lot of repairs because of this design. If a cable is pulled hard or tugged, it rips the soldering off the board.
So overall this camera has a more sturdy construction, with the addition of the pegs interlocking each panel of the bodies shell. And also is a lot more complex on the inside, more connectors, more cables, more screws, and more difficult to take apart and work on. Which users really won't notice, but definitely will make any repairs a little more tougher for the repair techs.
To read the entire LensRentals article, see all there photos, or even rent the new 5D Mark IV and take it for a test drive, click on the link below and head over to their site.