Hi There
I seem to have the same issue iwth my N5. I tried to buy a replacement cover but it didn't work at all. I also tried to scrape the black stuff away, but hadn't that much success with it.
So my question goes to Greg; how did you scrape that stuff off? I tried using a cutter - I didn't want to use heavier tools because these spring contacts seem very fragile. Should I give it a try with a nail file?
Thanks!