I recently installed Ubuntu 14.04 and was setting up the peripherals. All went well and the scanner was recognized right away though as a Scanjet 4850C instead of a 4890.
I tried simple scan and only got black. I tried various settings and with a fresh start of Simple Scan, I was able to scan at 150dpi greyscale only. I read some helps on the web and they suggested XSane. I installed that and can now scan in both colour and greyscale but still only at 150dpi. Any other resolution results only in a black image.
Any help would be appreciated. I think this is a bug that many need some updates.