My EZFlash Jr has randomly stopped working after being in storage for 2-3 months. It was in dry, waterproof plastic container with the rest of my GB carts and hasn't been knocked about.
When it starts up, it shows a black bar + (R) instead of Nintendo logo on boot.
I have tried the following...
I may try the new ram site, and download more RAM to my Switch. Not sure if ddr3 is the right ram
for it tho. Edit- no it uses floppy Ram, just like @AncientBoi