What's wrong with my shifter? This is a Nexus 7 spd hub gear twist shifter integrated in the brake lever. I had to undo the gear cable to get my rear wheel out. I therefore turned the bicycle upside down (some say that this alone can wreck this type of shifter). I reinstalled the cable on the hub, but ever since the shifter won't work. I re-undid the gear cable at the hub end and now nothing seems to work anymore: arbitrary amount of cable length that I can pull out at the hub end (but never enough to reinstall the gear cable on the hub) and arbitrary amount of positions I can click the shifter in, no matter what I do (gear cable adjustement bolt completely in or out etc....). Is this shifter broken or am I missing something?
Looks like the barrel adjuster has been broken off and has floated down the shift cable, so the shifter end of the cable housing is not anchored.

The shifter unit should look like this 



You might be able to glue the inner barrel back on to the shifter body. The housing is pulled back into the shifter so the glued joint would be compressed rather than pulled apart.