I see that Tm's request met with a deafening response.
I'm hoping to give a bike to a friend. It's a Ridgeback Nexus 8-speed which I bought new about 16 years ago for my daughter, but she rode it very little. It has the thumb shifter, but neither button is having any effect. The cable is clean and moves freely - I have proved this by simply grabbing hold of the outer and pulling it away from the shifter.
The bike has been sitting unused in my garage for almost all of its life.
This is the type of shifter in question.
Has anyone worked on one of these? Have any useful tips? Thanks in advance.