I just replaced a cheap old Canon LiDE 30 flatbed scanner with a cheap new LiDE 120, only to get flat-black scans. The machinery worked (yes, I released the travel lock), everything seemed fine, the images were the proper size, but they were dead black.
Of course, the scanner worked OK on the Token Windows Box, but wow what crappy software they include.
Turns out the LiDE 120 requires the latest-and-greatest version 1.0.27 of the various SANE programs & libraries. Mercifully, getting those didn’t require compiling from source, just setting up the maintainer’s PPA of the most recent stable release:
sudo add-apt-repository ppa:rolfbensch/sane-release sudo apt-get update sudo apt-get upgrade
Which introduced circular dependencies with the distro-installed version 1.0.25 files, which I solved by ripping the entire SANE Thing out by the root(s) and reinstalling it to (re)synchronize All The Things:
sudo apt-get remove libsane:i386 sane sane-utils xsane libsane-common ia32-libs libsane sudo apt-get install libsane:i386 sane sane-utils xsane libsane-common ia32-libs libsane
And then It Just Worked:
Of course, you must keep this WARNING in mind:
Franklin didn’t know about scanners or color laser printers when he observed:
Those who would give up essential Liberty, to purchase a little temporary Safety, deserve neither Liberty nor Safety
Of course, there’s more to the story, but one should:
The Smell of Molten Projects in the Morning 
Let me throw in a plug for a fellow Ed’s Vuescan – runs on Linux, supports almost every scanner made, and frequently gets better results than anything else, particularly if you want to scan photos or film. https://www.hamrick.com/
Thanks for the heads up. I still use an old LiDE but I’ll bear this in mind when/if I upgrade.