Hi Zach!
When both screens are flickering, then both screens their ribbon cables are not all the way in/properly connected OR they are damaged.
The ribbon cables need to go all in the connector, when they are in, you actually need to carefully give them a light push to get them further in..
When the screens give you a white flash and turns off, it's always the ribbon cable.
Good luck with the repair, and let us know how it goes!