@rak7145 said in RetroPie won't boot on Raspberry Pi 3:
I encountered an error numerous times that said Etcher couldn't locate the disk
I haven't had this happen myself though it's possible there's something up with your SD card/ SD card reader. There are lots of shady eBay SD sellers, I try and stick with reputable sources, if you have another microsd laying around might be worth trying and if for some reason it's etcher you can try win32diskimager instead to rule that out as well though I personally have never had issues with etcher.
If above fails also try diff HDMI if possible but I wouldn't necessarily go buying all sorts of new hardware until I've tried every software fix.