Macbook Pro 2015's screen flashes up and down I got my Mid-2105 15" MacBook Pro a year or two back. It worked great, and I even got a free battery replacement from Apple. However a few days ago it was dropped on the floor. At first, the Mac was not taking touch pad input and most of the keyboard (although at least some functions keys worked) wasn't working, even after restarting.  

However, a bit later the keyboard and touch pad started working again. At that point I noticed that the screen was "flashing". Basically the image on the display would randomly flash to some point below on the screen, then flash back to it's normal position, and so on. This flashing happens as soon as the Apple logo is displayed at startup, and applies even to the dead battery logo. 

I Googled the symptoms, but all of the results seemed to be for software issues, not hardware. I might've gone to the Genius bar, but they're all closed due to the pandemic, and with everyone quarantined at home, now is not a great time for the computer to not function. 

I also noticed that when you look closely, there are also random pixels that get turned on to full brightness after the screen flashes.

So please, if anyone has any idea of went wrong or how to fix it, I'd really appreciate it. I do have some very basic experience in opening up mobile devices, so if a fix isn't too far out of my realm I might give at try. 

Here is a video of the problem in action.
Basically the image on the display would randomly flash to some point below on the screen, then flash back to it's normal position, and so on. This flashing happens as soon as the apple logo is displayed at startup, and applies even to the dead battery logo. 


This is a hardware issue - it's likely the LCD or back light is damaged in some way.  If you're seeing this on startup that means it's happening prior to software being (fully) loaded.


  ... a few days ago it was dropped on the floor. 


That would be the cause.  I've seen this (well variations of this) numerous times.  The best way to confirm this is to "remove" the LCD from the equation - plug in an external monitor.  If there's no flashing there, it's the LCD.

Fix

You need to replace the LCD. It may be the back light, but I doubt it. You'll need an LCD Assembly.  iFixit.com has an excellent step by step guide on replacing it.  If this is not your cup of tea, I definitely recommend taking/sending it in for repair.  You may need to source this from eBay or similar to get the best price - these run in the $4-600 (USD) price range