I wrote this a year ago. Still not solved, so I have re-written it to reflect the current state.
System:
Ubuntu 16.04 LTS, and a Canon Pixma MG5751 multifunction printer/scanner on USB.
Problem:
Printer works perfectly. Scanner is the same USB device but not recognized by sane, but works fine with Canon's scangearmp2. The scanner has worked perfectly with Ubuntu earlier, even using Simple Scan; I have no idea what changed.
Please:
How can I get the scanner working under sane again?
Steps so far:
- I have removed and re-added the printer several times.
- I have also purged and reinstalled the Canon
cnijprinterandscangearmp2packages in between. - Reading around other very similar questions, I've found that my computer does recognize the device.
lsusb|grep Canonprovides:
Bus 001 Device 003: ID 04a9:178e Canon, Inc.sane-find-scannerfinds nothing but complains about insufficient permissions.sudo sane-find-scanner|grep Canonfinds the device:
found USB scanner (vendor=0x04a9 [Canon], product=0x178e [MG5700 series]) at libusb:001:003sudo scanimage -Ldoes not find the scanner, and neither does Simple Scan:
No scanners were identified. If you were expecting something different, check that the scanner is plugged in, turned on and detected by the sane-find-scanner tool (if appropriate). Please read the documentation which came with this software (README, FAQ, manpages).
I'm out of ideas. Please help! Thank you.
Update based on comments: I've installed the sane-git package and tested: no success. Scangearmp2 works but Simple Scan still doesn't see the scanner. The sane-git page also linked to the latest release version sane-release which I also installed, and that caused a lot of promising lines like Installing new version of config file /etc/sane.d/canon_dr.conf ... - but the result was the same; Scangearmp2 works but Simple Scan still doesn't see the scanner.
Update 20190122:
After an hour of working with apt-get I have now made some progress, but only partially.
scanimage -Lnow finds the scanner, even withoutsudo:
device `pixma:MG5700_192.168.1.81' is a CANON Canon PIXMA MG5700 Series multi-function peripheral device `pixma:04A9178E_733AA7' is a CANON Canon PIXMA MG5700 Series multi-function peripheral
- When I start Simple-Scan, it does not immediately complain about no scanner found. This is good.
- When I start a scan, it complains: Failed to scan: Error communicating with scanner.
- In Simple-Scan > Document > Preferences, I see that there are two scanners listed, and the first one is selected. I selected the second choice and tried again = SUCCESS! I guess it doesn't like the network scanner but USB works. I'm happy!