I had the stuck white pixels from with the DMD chip on my WD-65734. It got replaced by a local service provider and the pixel problem is now gone. However, afterwards, I noticed a shadow smudge located in the upper center of my screen that is visible when the image has a light background. The image is also rotated 1-2 degrees to counter-clockwise.
I'm certain the shadows weren't there prior to the DMD replacement and there may have been some of the rotation/geometry problem but not as pronounced as it is now. Neither the service provider nor the manufacturer will take responsibility for these problems introduced during the installation process because they consider it a "light engine problem" which means full replacement, even though it probably doesn't have to go that far.
For the shadows, I suspect dust got on the chip or inside the light engine when we dusted the fans.
I'm pretty technical and also watched the tech install the DMD chip 3 times already (first time it didn't work, second was reinstall of the old chip to confirm tv was working, third was reinstall of the new chip that worked this time) so I'm pretty confident I can pull out the light engine to check for dust on the chip.
But, if it is not directly on the chip, where else should I look? I've seen some other posts where people disassemble the light engine more to clean stuff inside. I did check inside the box behind the screen but the mirror looks pretty clean and anything there seems to cast a sharp edge shadow so given how unfocused the shadows are, I suspect they are farther back in the light optics chain.
For the rotation/geometry, I tried the service menu recalibration process, but the top right corner is too far outside the bezel to even bring the cross back onto the screen. Also there is no rotation correction. Any tips on how to adjust this?
Pictures of the problems:
Shadow smudge with less image correction. The background is pure white, the blue gradient is an artifact of the picture-taking. There are two smudges, one on the bottom and a separate one at the top. Each is about 3x3" in size.
Smudges with more image processing to make them more visible.
Picture of the whole image. There is some distortion from the camera lens but you can see the rotation and geometry problem relative to the TV's bezel.