My wife’s Google Pixel 5A phone developed a problem where the screen would “flash” between a colorful snow pattern and was it was supposed to be showing. It started out slowly, with intermittent flashes, but quickly got worse where the screen was barely ever showing what it was supposed to. [It also does not accept touch input events when “flashing” the colored snow pattern..]

I was able to retrieve the data off of the phone by heating the entire phone up, but this was a temporary fix as the problem returns as soon as the phone cools down.

I was able to fix the problem (hopefully permanently) by completely disassembling the phone, extracting the motherboard, and hitting it with 5 minutes of heat from a 300 deg c hot air rework station. (I aimed the hot air at the video connector, and then at the covered set of chips right above the video connector (opposite from the battery connector), as I figured that was the most likely location for the video graphics chips. I still don’t know which EXACT component had the problem, but allowing the solder joints in that general area to re-flow appears to have fixed the problem, as when I re-assembled the phone it is working perfectly at room temperature.