I am currently running 6.11.5. My power supply failed and once I replaced it, I could no longer access the webui or ssh in to the server. Pings to the ip address did not go through. I logged in locally and was able to run a diagnostics log. I changed the Use SSL setting to "no" and trying to access the webui via http was not successful. I then attempted to ping 8.8.8.8 as well as my router IP but neither succeeded. At this point I am not sure what the check next.
It may be unrelated, but I noticed that my diagnostics file is dated 2010, so perhaps something went awry on the motherboard itself when the power supply failed?
diagnostics-20100104-1914.zip