Alistair, can you do another test:
Power-cycle the printer and do print jobs. After each print job run ONLY
sudo time /usr/lib/cups/backend/usb
Can you keep printing without power-cycling the printer now?
Now power-cycle the printer and print several print jobs but run ONLY
time lsusb
after each job. Can you keep printing without further power-cycling?
In any case, please post the screen output and attach error_log. Do not compress any files which you attach.
Please do the second test also if you are able to keep on printing in the first test.
Alistair, can you do another test:
Power-cycle the printer and do print jobs. After each print job run ONLY
sudo time /usr/lib/ cups/backend/ usb
Can you keep printing without power-cycling the printer now?
Now power-cycle the printer and print several print jobs but run ONLY
time lsusb
after each job. Can you keep printing without further power-cycling?
In any case, please post the screen output and attach error_log. Do not compress any files which you attach.
Please do the second test also if you are able to keep on printing in the first test.