simple-scan sees the USB-powered scanner (CanoScan LiDE 110) but sometimes fails to start it up.
Usually it scans the first page in several "tries", i.e., the "scanning noise" comes out in bursts, interrupted by short pauses, and then scans the page. The second and further pages are scanned in a single burst of "scanning noise".
However, sometimes, I get a very short burst of noise and then an error message. When I connect the scanner to a mac laptop, it pauses with the "warming up the scanner" message and then scans the page.
When I immediately re-connect the scanner to Ubuntu, simple-scan works just fine.
Is there a way to teach simple-scan to "try harder" when warming up the scanner?
PS. Changing cables and USB ports does not help.
SOLUTION: plug the scanner into the usb2 socket and leave it alone for a few minutes!
I have the same scanner and works every time and never had any real trouble with it. The scanner is powered by USB only and there lies the most likely cause of your trouble. Some laptops only provide limited power to most of the USB ports and some cables with some age and/or wear might have lost the ability to provide the power needed. When using a laptop, try to check the USB ports. Most laptops have some ports with an icon of a lightning bolt that suggests the port is capable of providing enough power for USB devices that need it. Also, try another cable or if none available, try clean the connectors to make sure they are dirt free.
Most trouble for these USB devices comes simply because they get underpowered and give weird results or behave badly at moments they just need for a little more.
Good luck!