I took my ergobrain equipped bike out today and wouldn't you know it had a problem. display was working but not responding to the lever buttons or showing gears.
after much fiddling, looking at the manual, and more fiddling, noticed the battery icon was on. put in new battery, re-learnt the gears, all OK.
in looking at the manual, as well as the self learning feature, if you are not using cadence feature you can still input the sprockets manually. suggest OP downloads the manual.