I have had this happen to me roughly a half dozen times where all of my dockers will be unresponsive so I will head to the gui and it isn't available, I cant ssh into it, its not pingable on the network.  The cursor is blinking on the console but the keyboard will not work, thus I am forced to do an unclean shutdown.  Start it back up and wait hours for a parity check to happen.  I have not been able to pinpoint what is going on, its annoying and I am afraid it will cause issues with my array.  Any help would be beneficial.  Please advise on what I can do to aid in troubleshooting the issue.

homeserver-diagnostics-20180907-1947.zip

Install the Fix Common Problems plugin and turn on its trouble shooting mode. 

 

Open up the case and see that all of the fans are running and clean the inside with compressed air.  (Do this where the voluminous volume of dust and dirt won't be an issue.)  Run a 24 MemTst (unless you have ECC memory).  Power Supplies  have been implicated in few cases with problems like this.  Does yours have enough capacity on the +12V rail(s)?  Could it be simply be old and tired?