Replacement RPi 3B fixed the problem. Chalking it up to a bad DSI header.

Thanks for your help!

The solder joints look pretty good, but the DSI header is on just a little bit crooked: http://i.imgur.com/8hm0dL4.jpg (embiggened) It doesn't seem like that'd cause a problem all on its own, but I'll round up another RPi 3B and see if that solves the problem (unfortunately, I don't have a multimete...

Yes - never installed them as I don't think they're required for the 3B. I only had the GND/+5V leads attached. I've tried several different combinations of powering the boards -- using the same 2.5A power supply with the red/black leads in place as well as using different power supplies for each bo...

Well, I've gotten a replacement and this one has the exact same problem (except worse somehow). Is there a chance the Pi itself could be the source of the problem?

Hi Everyone! I have an official 7" touch screen for my Pi 3B which has some video quality problems: https://youtu.be/XKevqDokCHw Does anyone recognize this and/or know which component may be to blame? I have bought another screen and will likely return this one as defective, but I'm curious which co...