? kenko tubes nikon

teamracephotos

Hey anybody out there own a set of kenko tubes for nikon. I have had a set for the past 4 years, love them, but both my 12mm amd 20mm (the ones I use the most) have stopped working. I can not change the apperture. I have tryed both on two different camera bodies. It feels like a spring has broken on one of the arms inside. I used these almost everyday the past four years so I am not complaining. Was just wondering if anybody out there has had the same issue, and maybe might know how o fix it.
Thank you for your time Mark