CSMicros

Purgeable space means its being used but the OS will automatically free it up if needed. The primary example of this is cloud storage. With iCloud storage, Mac OS will automatically download the files to the hard drive if there's room. But if you start filling up the hard drive with other stuff it will delete the locally stored cloud files as needed to free up space.
 
 

The very first thing to do is go back to a place where it worked.
 
Remove the button and just clip the screen back in, if that doesnt work try another screen to rule out the new one you have isnt faulty.
 
If not then put the old screen back on and go through dfu reset again.
 
The other issue you have is if you didnt use any antistatic pads, straps etc then there is a good chance youve fried a chip on the board.