NANDJ_ Find flash media and keep out ERROR FIX!
If you are ever messing around with your iPhone 5 and put it back together, you may come across the "cannot find flash media" or "FIND flash media and keep out" error —and this will not let you boot properly. It gives you the red screen of death, but it can also just give you the error code and then restart or just show the Apple logo and then restart.
I found the fix, finally. I believe I am the first to find this, and it is relatively simple to fix. This is probably my first post on the internet that can actually help a majority of people that I've seen with this error and no fix for it yet. So from what I've experienced it's due to your front camera sensor assembly connector being damaged. The connectors on these things are extremely fragile and the connector seems to bow like a banana fairly easy.
So here is a way to try to narrow down the problem. Hook up only the LCD/Digitizer connector only, and "hard reset your phone" and see if it starts back up. If it does, then you've found out that it's for sure the front camera connector.
There are 2 parts to this 3rd connector. The Proximity SENSOR and the FRONT CAMERA are soldered together like an assembly. I highly recommend purchasing the assembly (front camera and proximity sensor) and not just the front camera flex cable, as it is EXTREMELY DIFFICULT to install. And I mean DIFFICULT.