CUPS Failed to Connect to Server
 

I have Ubuntu 16.04LTS 64 bit.
My Canon Pixma iP4950 was working fine but after a partial update, the CUPS file packed up.
When trying to access the printer, I get the report
'Printing Service Not available. Start the computer on this computer or connect to another server'

Also, I have removed 'Printers' from the system and reinstalled same.
I have also been through long and laborious Terminal sessions including reintstalling cups

I do not know how to 'start the service'
On pressing the connect button, the drop down menu reads:
/var/run/cups/cups.sock.
Can anyone help please - I am not familiar with any text authoring or modification in the terminal other than copying and pasting from those that know
Thank you

I'm not the best with printers but I'll share with you what works for me when my printer won't work. Having said that this is the limit on what I can tell you to try.

Go to http://localhost:631 then select Printers.
Select the printer, then Maintenance, then Cancel all Jobs (just to make sure there are no pending jobs) Then select Administration, then Delete the Printer.
Exit Cups

Re-install the Printer and it should print for you. Maybe try:
https://help.ubuntu.com/lts/serverguide/cups.html
http://www.novell.com/documentation/...l/ch05s07.html
http://togaware.com/linux/survivor/CUPS_Command.html

What distribution are you running? Ubuntu?

Thank you.
I have tried to get to 'localhost:631', but my browser (Firefox) reports 'Unable to connect'
Downloading and trying Chrome has the same effect
I have also tried the command line you suggest - no cups!!

I am rapidly coming to the conclusion I am going have to copy everything on the computer and undertake a clean install.

Run this in your terminal as 'root':
Than try going to localhost:631 and it should work. Did for me when I got unable to connect.

just a couple of ideas...
 

You wrote the update was only partial. - Have you tried a complete one? As inand maybe even(At least with Unity the Ubunty (12/14/16) dependency handling seems buggy.)

Have you checked that cups is not running any more before trying to restart it?or something like
Anything suspicious in the log files in /var/log/cups/ (especially error_log) right after (re)starting cups? (That's where they are on my Debian Sid. Most likely very similar on a *buntu.)