Quick debugging of a Linux printer via cups command line tools

Step by step cups debugging ( here with a network printer)

Which printer queue do I have configured ?
lpstat -p
printer epson is idle.  enabled since Sat Dec 24 13:18:09 2017
#here I have a printer called 'epson", doing nothing, that the cups daemon considers as enabled

Which connection am I using to get to this printer ?
lpstat -v
device for epson: lpd://epson34dea0.local:515/PASSTHRU
# here the locally configured 'epson' printer queue is backed by a network device at the adress epson34dea0.local, to which I am sending my print jobs via the lpd protocol

Is my printer ready ?
lpq
epson is ready
no entries
# here my local print queue 'epson' is accepting print jobs ( which does not say anything about the physical device, it might be offline

If here you local print queue 'epson' is not ready, you can try to reenable it in the cups system with:

sudo cupsenable epson

If you notice that the printer is disabled all the time, because for instance of a flaky network, you can edit /etc/cups/printers.conf and change the ErrorPolicy for each printer from stop-printer to retry-job.
It should be also possible to set this parameter in cupsd.conf

Finally you can print a test page with
lpr /usr/share/cups/data/testprint