Posted: Tue May 27, 2025 1:25 Post subject: USB/network printer stopped working and lpr.err in syslog
Recently, the network USB printer has stopped working (it worked just a few days ago!), and the syslog is full of these messages, repeated every 10 seconds:
Quote:
R6900 lpr.err p9100d[2763]: /dev/lp0: No such device
R6900 lpr.err p9100d[2763]: /dev/lp0: No such device, will try opening later
This USB network printer (Brother HL-2040) was set up and working since years, via the USB port on the Netgear R6900/R7000 and dd-wrt's USB and printing features, i.e. Core USB support, USB Printer support, and USB Storage support are all enabled.
I've rebooted both the router and printer. Via SSH, I killed the process for `2763 root {p910nd} p9100d -f /dev/lp0 0` and checked that it reappeared eventually (maybe after I disabled/re-enabled USB/Printer support in the webgui). I have not messed with any dd-wrt/network/printer configurations. I also bypassed an active USB extension cable and plugged the printer directly to the router. I tried printing from Windows and Linux computers and none succeed. Nothing has so far made any difference. I printed a test page directly from the printer (press Go button 3 times), so it's not like the printer is dead, out of paper, out of toner, or something basic like that.
Thoughts what else to check or what the issue might be?
Last edited by fizikz on Tue May 27, 2025 2:17; edited 1 time in total
Well this is bizarre... the problem turned out to be the active USB cable.
Yes, I thought I bypassed it before.. But this time, while SSH'ed into the router and running "watch -n1 lsusb" to monitor USB connections, I was able to see the printer get recognized when plugged in directly to the router, but (mostly) not when plugged into the active USB extension.
The USB extension cable still seems to work when plugging in a mouse. I suppose the active component might be dead or flaky.
Ideally, sure, but the printer isn't near the router.
What didn't work well was a passive extension cable, which partially worked when I first configured it, but then resulted in garbled printed pages later in actual use. The active USB extension replaced that, and worked fine since 2021, until today.
