[sf-lug] SF-LUG meeting notes for Monday 21 January 2019

[Rick Moen]

Quoting Bobbie Sellers (bliss-sf4ever at dslextreme.com):

>>> I don't find that directory?
>>
>> Um, 'directory'?  I'm sorry, what are you talking about?
>
> Well it finds a blank page.

You mean, attempting to load http://localhost:631/printers/ , or
http://localhost:631/ , using a Web browser _on the CUPS host_ produces
a blank page?  Not a 404 not found?  

That doesn't appear to add up, Bobbie.  If there's nothing there, you
wouldn't get a 'blank page', but rather a 404 response.  I think you
must be doing something odd.

On any machine where the CUPS service is running, loading
http://localhost:631/ should immediately bring up the standard CUPS
administrative interface.  The http://localhost:631/printers/ page is a
subpage you would visit after authenticating on the main page.

Given the assumption that you have the CUPS daemon running on your
system -- and, by the way, do you? -- then that famous admin WebUI will
be sitting there cheerfully peeking out of port 631 on the localhost 
network interface -- and is the standard place to check on, configure,
and diagnose CUPS.  The only way I'm aware of to disable access to 
that Web interface that I can think  of would be to comment out or
remove the 'Port 631' or 'Listen localhost:631' lines in
/etc/cups/cupsd.conf, or via some very inept firewalling, but who would
do that?

> Actually I never claimed any knowledge of CUPS....

I never said you 'claimed knowledge of CUPS'.

On the flip side of that, I've been trying to show you some very
relevant things.  I'm puzzled that this has resulted in you trying to
argue.  This doesn't seem very useful.


>>> But searching on printers I find the following
>>
>> You found that where?  Is this a file on your system?  If so, what file?
>> It looks like it could be your /etc/cups/printers.conf file -- but I'm
>> mystified about why specifically you posted that.
> 
> Because that is what I could find.

Again, you do not bother to _even_ say what file this was.  If you want
people to be able to assist you, it's not in your interest to 

But anyway, assuming you're quoting from your system's
/etc/cups/printers.conf file, that tells you nothing about whether the 
Gutenprint RPM package providing relevant print filters is installed.
OTOH, as I already detailed, you can find that out using the rpm
command -- as I see you now did:


> But using the command you recommended here is the result:
> [bliss at bliss ~]$ rpm -qa | grep -i gutenprint
> gutenprint-ijs-5.2.10-1pclos2014
> lib64gutenprint2-5.2.10-1pclos2014
> gutenprint-common-5.2.10-1pclos2014
> gutenprint-foomatic-5.2.10-1pclos2014
> gutenprint-escputil-5.2.10-1pclos2014
> lib64gutenprintui2_1-5.2.10-1pclos2014
> gutenprint-cups-5.2.10-1pclos2014
> gutenprint-gimp2-5.2.10-1pclos2014
> 
> and for foomatic
> [bliss at bliss ~]$ rpm -qa | grep -i foomatic
> foomatic-db-4.0-2.20180120.1pclos2018
> foomatic-filters-4.0.9-2pclos2018
> gutenprint-foomatic-5.2.10-1pclos2014
> foomatic-db-engine-4.0.12-1pclos2018

It sure seems likely from were I'm sitting that the foomatic-filters
package provides the Gutenprint filters.  So yay.  One variable nailed
down.

You know, since you're using an RPM-based distribution, it's in your
interest to learn a bit about use of the rpm tool.  For example, 

   $ rpm -qi foomatic-filters

...would do a 'query info' operation, telling you some useful bits of
short information about the package including a description of the
contents.


> >Well, it's your call wether you want to give up on your printer, but you
> >might want to do basic hardware diagnosis before throwing it away.
> >Does the LCD display screen indicate a hardware problem?  Does the
> >http://localhost:631/printers/ screen appear to show the printer as
> >online and reachable?  Does it pass a self-test?[1]  Can you have CUPS
> >send it a test page and have it comply?
> 
> It has printed nothing* and the LCD screen does not allow for much
> non-maintenance information.

I would have imagined that the LCD screen's maintenance information
might be of keen interest.  For example, it's supposed to tell you
whether it detects a printer error, or a scanner error, or it thinks the
ink pads are near the end of their service life and need to be replaced,
and it has various setup subscreens you're supposed to be able to go
through.  If the LCD screen doesn't do any of that, then the printer
evidently has a major electrical problem and is probably very dead
unless perhaps there is just a blown fuse.  If it _does_ have those
intended functions, then they can be used to check for problems, e.g.:

1.  Disconnect USB cable from the host computer.
2.  Load plain paper.
3.  Press Setup on the LCD screen, then arrows to select Maintenance,
    then Nozzle Check, then OK.  Then press Start.  
4.  Printer should test-print a nozzle test pattern.  

If it doesn't print the test pattern, then the printer probably has a
genuine mechanical problem.  If it does, then they say 'Your problem may
be caused by your computer, cable, software, or setting selections',
which sounds plausible enough.


> *That includes running the usual test page, the self-test of the
> nozzle pattern and the print head cleaning routine.

Well, if the nozzle test pattern ('Nozzle Check') is selectable but
results in no print action, then I agree that it looks like a
mechanically challenged unit. 


> >[1] https://files.support.epson.com/htmldocs/nx510_/nx510_ug/wwhelp/wwhimpl/js/html/wwhelp.htm
> 
>     All I see there is a blank page with a vertical line about
> 1/5 of the way from the left side of the screen.

Um, something's very wrong on your end.  This page _does_ require Flash
for the right hand side (to the right of the vertical divider), but the
'Contents' column on the left is regular old HTML5.

Those Epson pages are pretty decent.  Whatever's preventing you from
seeing them, you really should track down and fix, lest you be unable to
see other significant Web sites you care about more.


>     As I may have mentioned elsewhere I will try another
> distribution on the printer to see if perhaps some
> reaction can be coaxed from the NX515.

Um, whoa.  If the printer is indeed (as I think you said) failing Nozzle
Check, it really can't be a problem with your computer, can it?